Reiindex_axis with copy=False return new object when expecting to change it inplace
I thought that `reindex_axis` with argument `copy=False` should change it inplace. From [docs](http://pandas.pydata.org/pandas-docs/version/0.17.0/generated/pandas.DataFrame.reindex_axis.html):

> **copy** : _boolean_, _default True_  
>     Return a new object, even if the passed indexes are the same

However:

```
df = pd.DataFrame({'A': [1], 'B': [2]})

In [105]: df.reindex_axis(['B', 'A'], axis=1, copy=False)
Out[105]:
   B  A
0  2  1

In [106]: df
Out[106]:
   A  B
0  1  2
```

Am I misunderstood that argument?
