Fix bug where ``nanops._has_infs`` doesn't work with many dtypes (issue #7357)
Fixes issue #7357, where where `nanops._has_infs` doesn't work with many dtypes

Travis CI passes, but this does NOT include the fix for the bug mentioned in #7440
 ok, need to fix #7440 first
 This version should fix the bug identified in #7440.
 closer

```

C:\Users\Jeff Reback\Documents\GitHub\pandas>c:\python27-64\Scripts\nosetests.exe build\lib.win-amd64-2.7\pandas\tests\test_nanops.py
......C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\core\nanops.py:197: ComplexWarning: Casting complex values to real discards the imaginary part
  return ~np.isfinite(values.astype('float64'))
................EF.E......
======================================================================
ERROR: test_nanmax (pandas.tests.test_nanops.TestnanopsDataFrame)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 320, in test_nanmax
    allow_str=False, allow_obj=False)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 241, in check_funs
    self.check_fun(testfunc, targfunc, 'arr_tdelta', **kwargs)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 202, in check_fun
    testarval, targarval, targarnanval, **kwargs)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 188, in check_fun_data
    **kwargs)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 188, in check_fun_data
    **kwargs)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 160, in check_fun_data
    **kwargs)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\core\nanops.py", line 88, in f
    result = alt(values, axis=axis, skipna=skipna, **kwds)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\core\nanops.py", line 422, in nanmax
    return _maybe_null_out(result, axis, mask)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\core\nanops.py", line 553, in _maybe_null_out
    if null_mask.any():
AttributeError: ("'bool' object has no attribute 'any'", 'axis: 0 of 0', 'skipna: False', 'kwargs: {}', 'testar: arr_tdelta', 'targar: arr_tdelta', 'targarnan: arr_tdelta')

======================================================================
ERROR: test_nanmin (pandas.tests.test_nanops.TestnanopsDataFrame)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 315, in test_nanmin
    allow_str=False, allow_obj=False)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 241, in check_funs
    self.check_fun(testfunc, targfunc, 'arr_tdelta', **kwargs)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 202, in check_fun
    testarval, targarval, targarnanval, **kwargs)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 188, in check_fun_data
    **kwargs)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 188, in check_fun_data
    **kwargs)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 160, in check_fun_data
    **kwargs)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\core\nanops.py", line 88, in f
    result = alt(values, axis=axis, skipna=skipna, **kwds)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\core\nanops.py", line 392, in nanmin
    return _maybe_null_out(result, axis, mask)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\core\nanops.py", line 553, in _maybe_null_out
    if null_mask.any():
AttributeError: ("'bool' object has no attribute 'any'", 'axis: 0 of 0', 'skipna: False', 'kwargs: {}', 'testar: arr_tdelta', 'targar: arr_tdelta', 'targarnan: arr_tdelta')

======================================================================
FAIL: test_nanmean (pandas.tests.test_nanops.TestnanopsDataFrame)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 290, in test_nanmean
    allow_str=False, allow_date=False)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 216, in check_funs
    self.check_fun(testfunc, targfunc, 'arr_int', **kwargs)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 202, in check_fun
    testarval, targarval, targarnanval, **kwargs)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 161, in check_fun_data
    self.check_results(targ, res, axis)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 124, in check_results
    tm.assert_almost_equal(targ, res)
  File "testing.pyx", line 58, in pandas._testing.assert_almost_equal (pandas\src\testing.c:2465)
  File "testing.pyx", line 93, in pandas._testing.assert_almost_equal (pandas\src\testing.c:1793)
  File "testing.pyx", line 93, in pandas._testing.assert_almost_equal (pandas\src\testing.c:1793)
  File "testing.pyx", line 136, in pandas._testing.assert_almost_equal (pandas\src\testing.c:2299)
AssertionError: ('expected -2.00000 but got -1.63636, with decimal 5', 'axis: 0 of 2', 'skipna: False', 'kwargs: {}', 'testar: arr_int', 'targar: arr_int', 'targarnan: arr_int')

----------------------------------------------------------------------
Ran 32 tests in 1.047s

FAILED (errors=2, failures=1)

C:\Users\Jeff Reback\Documents\GitHub\pandas>
```
 That is a separate problem resulting from the same underlying issue with scalars being converted to python native objects.  I am making a fix for these new issues now, but I don't think there is any way for me to fix it generally.

Can you do me a favor and tell me what happens when you do these:

``` Python
a=np.zeros(11).astype('bool')
b=a.shape[0]
type(b)
```

``` Python
a=np.zeros(11).astype('bool')
b=a.sum(0)
type(b)
```

``` Python
a=np.zeros(11).astype('bool')
b=a.shape[0] - a.sum(0, dtype=a.dtype)
type(b)
```

Whatever the case, this seems to be an upstream numpy issue.  I can work around it easily enough here, and I can't find any more code in `nanops` that looks like it will trigger it, but there is no telling where else it might appear.  You should probably see if you can reproduce it in numpy 1.9rc, and if so report it upstream.  I can't reproduce it on any of my setups so there isn't any point my reporting it.
 This version should also fix the new issue.
 windows is an odd beast - numpy does some odd things like type conversions (because the windows default int is int32 EVEN ON 64-bit), really weird. not a numpy bug but just some idiosyncratic behavior.

here's the results..

```
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

C:\Users\Jeff Reback>c:\python27-64\python
Python 2.7.5 (default, May 15 2013, 22:44:16) [MSC v.1500 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy as np
>>> a=np.zeros(11).astype('bool')
>>> b=a.shape[0]
>>> type(b)
<type 'long'>
>>> a=np.zeros(11).astype('bool')
>>> b=a.sum(0)
>>> type(b)
<type 'numpy.int32'>
>>> a=np.zeros(11).astype('bool')
>>> b=a.shape[0] - a.sum(0, dtype=a.dtype)
>>> type(b)
<type 'numpy.int64'>
>>>
```
 ok fixed those other 2....last one is here

```
.................F........
======================================================================
FAIL: test_nanmean (pandas.tests.test_nanops.TestnanopsDataFrame)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 290, in test_nanmean
    allow_str=False, allow_date=False)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 216, in check_funs
    self.check_fun(testfunc, targfunc, 'arr_int', **kwargs)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 202, in check_fun
    testarval, targarval, targarnanval, **kwargs)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 161, in check_fun_data
    self.check_results(targ, res, axis)
  File "C:\Users\Jeff Reback\Documents\GitHub\pandas\build\lib.win-amd64-2.7\pandas\tests\test_nanops.py", line 124, in check_results
    tm.assert_almost_equal(targ, res)
  File "testing.pyx", line 58, in pandas._testing.assert_almost_equal (pandas\src\testing.c:2465)
  File "testing.pyx", line 93, in pandas._testing.assert_almost_equal (pandas\src\testing.c:1793)
  File "testing.pyx", line 93, in pandas._testing.assert_almost_equal (pandas\src\testing.c:1793)
  File "testing.pyx", line 136, in pandas._testing.assert_almost_equal (pandas\src\testing.c:2299)
AssertionError: ('expected -2.00000 but got -1.63636, with decimal 5', 'axis: 0 of 2', 'skipna: False', 'kwargs: {}', 'testar: arr_int', 'targar: arr_int', 'targarnan: arr_int')

----------------------------------------------------------------------
Ran 32 tests in 1.013s

FAILED (failures=1)

C:\Users\Jeff Reback\Documents\GitHub\pandas>
```
 ```
(Pdb) l
125             except:
126                 # There are sometimes rounding errors with
127                 # complex and object dtypes.
128                 # If it isn't one of those, re-raise the error.
129                 if not hasattr(res, 'dtype') or res.dtype.kind not in ['c', 'O']:
130  ->                 raise
131                 # convert object dtypes to something that can be split into
132                 # real and imaginary parts
133                 if res.dtype.kind == 'O':
134                     if targ.dtype.kind != 'O':
135                         res = res.astype(targ.dtype)
(Pdb) l
136                     else:
137                         try:
138                             res = res.astype('c16')
139                         except:
140                             res = res.astype('f8')
141                         try:
142                             targ = targ.astype('c16')
143                         except:
144                             targ = targ.astype('f8')
145                 # there should never be a case where numpy returns an object
146                 # but nanops doesn't, so make that an exception
(Pdb) p targ
array([[-1.63636364,  1.        , -0.54545455,  2.        , -1.90909091],
       [-3.27272727, -0.09090909, -3.54545455, -0.90909091, -0.90909091],
       [-0.90909091, -2.18181818, -0.45454545, -3.72727273,  0.27272727],
       [-1.72727273, -0.09090909, -0.09090909, -1.09090909, -3.63636364],
       [ 1.72727273, -4.18181818, -0.72727273,  0.        , -1.        ],
       [ 0.36363636, -0.72727273, -2.45454545,  2.72727273, -3.72727273],
       [ 0.81818182, -3.        ,  1.        ,  0.63636364, -0.72727273]])
(Pdb) p targ.dtype
dtype('float64')
(Pdb) p res
array([[-2,  1, -1,  2, -2],
       [-4, -1, -4, -1, -1],
       [-1, -3, -1, -4,  0],
       [-2, -1, -1, -2, -4],
       [ 1, -5, -1,  0, -1],
       [ 0, -1, -3,  2, -4],
       [ 0, -3,  1,  0, -1]], dtype=int64)
(Pdb) p res.dtype
dtype('int64')
```
 Similar thing again.  Try this version.
 Wait, no, give me a second.
 Alright, now try.
 same result
 Try this version please
 looks good!

ok...ping when passes travis and we'll get this in

thanks!
 Travis tests pass
 ok.gr8!
 Also fixes #7415 
