BDay and bday confusion.
Are BDay and bday the same? Is one of them deprecated or something?

```
In [48]: pd.datetools.BDay?
Init signature: pd.datetools.BDay(self, n=1, normalize=False, **kwds)
Docstring:      DateOffset subclass representing possibly n business days
File:           c:\python27\lib\site-packages\pandas\tseries\offsets.py
Type:           type

In [49]: pd.datetools.bday?
Type:           BusinessDay
String form:    <BusinessDay>
File:           c:\python27\lib\site-packages\pandas\tseries\offsets.py
Signature:      pd.datetools.bday(self, other)
Docstring:      DateOffset subclass representing possibly n business days
Call signature: pd.datetools.bday(other)
```
