ENH: Removing unnecessary whitespace when formatting to a HTML table.
Closes #4987.

The problem is that all formatters always call `_make_fixed_width`. So, the only solution I found is just to strip the unnecessary whitespace.

yep
 @jreback OK, I'll implement the additional justifications.
 It turned out easier than I thought. Hope I haven't missed something though...
 @alefnula can u add tests for the new justification options
 @cpcloud I changed the HTML tests so the None option is working... For the other, will something like this be enough?

``` python
In [2]: df = pd.DataFrame({'foo': [1, 2, 3], 'bar': [4, 5, 6], 'baz': [7, 8, 9]})
In [3]: print(df.to_string(justify='left'))
   bar  baz  foo
0  4    7    1
1  5    8    2
2  6    9    3
In [4]: print(df.to_string(justify='right'))
   bar  baz  foo
0    4    7    1
1    5    8    2
2    6    9    3
In [5]: print(df.to_string(justify='center'))
   bar  baz  foo
0   4    7    1
1   5    8    2
2   6    9    3
```
 Although, maybe `align` is a better parameter name than `justify` :-/
 There was some really weird code here... The alignment of the columns was done twice (sometimes even 3 times, which is ridiculous - recursive calls...) I really couldn't find the reason why so I removed that.

Also there is a bug in the current string column formatting. The column header is not aligned. The bug is also on the master branch. I'll try to fix it here if this patch can be accepted.

Example of the bug:

``` python
import numpy as np
import pandas as pd
ind = pd.date_range('2013-01-01', freq='H', periods=10)
df = pd.DataFrame(np.random.randn(10, 3), index=ind)
df = df.reset_index()
df['test'] = 'foo bar baz'
print(df.to_string(justify='left'))
```

Produces:

```
  index                0         1         2        test        
0 2013-01-01 00:00:00 -0.295496 -1.622709 -2.330210  foo bar baz
1 2013-01-01 01:00:00 -0.663977 -0.415800 -1.928071  foo bar baz
2 2013-01-01 02:00:00 -0.468839  0.106345  1.344761  foo bar baz
3 2013-01-01 03:00:00 -0.154564  0.146896 -0.322325  foo bar baz
4 2013-01-01 04:00:00  0.695505  0.900301  0.261876  foo bar baz
5 2013-01-01 05:00:00 -1.142544 -0.089581  2.180599  foo bar baz
6 2013-01-01 06:00:00 -0.806229 -0.766914 -0.852616  foo bar baz
7 2013-01-01 07:00:00  0.037000 -0.093492  1.208734  foo bar baz
8 2013-01-01 08:00:00  1.578699  0.067581  0.855523  foo bar baz
9 2013-01-01 09:00:00  1.707266  1.333138  1.185469  foo bar baz
```

You can see that the `test` column header is shifted...

Finally, maybe `align` is a better parameter name than `justify` :-/
 @alefnula i would put the column alignment in a separate issue.
 @cpcloud The problem is that I don't even know if that's a bug or a feature :D That's why I asked.
 @cpcloud ok to merge?
 @alefnula relize no release notes...can you add?
 @jreback I don't think this should be merged yet. The `justfy=None` doesn't actually work on `to_string` because it will realise that it's `None` and turn it to `right` (the default), so maybe it should be `justify='none'` instead of `justify=None`? `justify=None` should probably just revert to whatever is the default... Probably `right` should be the default as it was before these changes.
 you can just put justify = 'right' as the default which iirc was what it was
 That's fine with me :) I'll do it that way then. I should probably change the docs also. Just to add that the 'center' option is also available.
 @cpcloud this looks ok....so when you are ready can merge (as I believe you are waiting to merge something else)
 @jreback I just rebased it, didn't changed anything yet. :) There is one more problem with this (I'm really sorry to be such a hassle :( but I just don't want to break anything), docs:

```
justify : {'left', 'right'}, default None
    Left or right-justify the column labels. If None uses the option from
    the print configuration (controlled by set_option), 'right' out
    of the box.
```

But now `justify` justifies the whole columns, not just the headers :( And also I cannot use the `None` and just default to `right` because if it's `None` it will read the:

``` python
if justify is None:
    self.justify = get_option("display.colheader_justify")
```

If it's ok to change the functionality to justify the whole columns I need a sentinel for `no justification`. And probably read `get_option("display.column_justify")` instead of `display.colheader_justify`.

`display.colheader_justify` is mentioned in the docs so it will be a backward incompatible change..
 @cpcloud what do you think?
I think columns should be left alone and this just should apply to the header
 @jreback In that case this whole pull request should be discarded since it justifies the whole columns... I could maybe separate the column and header justification and use `justify` for header and `align` parameter for columns?
 do you want to defer this to 0.14....as templates hopefully will solve these types of things?
@cpcloud ?
 defering this to 0.14
 Stale, Please open an updated PR if the problems mentioned are sorted out.
