BUG: pprint_thing should pprint and limit nested sequences in dicts GH3251
#3251

**before**

``` python
pd.options.display.max_seq_items= 5
print pd.core.common.pprint_thing(dict(foo=range(100)))
foo = range(5)
foo[0] = foo
print pd.core.common.pprint_thing(dict(foo=foo))
{'foo': [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99]}
{'foo': [[...], 1, 2, 3, 4]}
```

**After**:

``` python

In [16]: pd.options.display.max_seq_items= 5
    ...: pd.core.common.pprint_thing(dict(foo=range(100)))
    ...: 
Out[16]: u'{foo: [0, 1, 2, 3, 4, ...]}'

In [17]: foo = range(5)
    ...: foo[0] = foo
    ...: pd.core.common.pprint_thing(dict(foo=foo))
    ...: 
Out[17]: u'{foo: [[[[...], 1, 2, 3, 4], 1, 2, 3, 4], 1, 2, 3, 4]}'
```

moved to 0.12 to be merge right along with #3038, to minimize possible test 
breakage for users due to a formatting flicker between merging this (change)
and that (change back, in another way).
 preemptive merger !
 hey what now?
 Jeff humor :)
 I'm trying to drag all y'all to a sane "merge window" type workflow,
and f*\* A if i'm not gonna lead by example.

I guess you meant to call me "mergerer!",  what a fun word to pronounce, rhymes well too.

Great work on 0.11 Jeff!
 U2 @y-p 
