Timestamp.to_datetime() crashes with win32timezone.TimeZoneInfo objects
Thanks to the wonders of duck typing, `pandas.Timestamp` happily accepts `pywintypes.TimeType` objects (otherwise known as `pywintypes.datetime`), including those that employ the `win32timezone.TimeZoneInfo` object. And most methods work. 

For some reason, `to_datetime` does not, and indeed it crashes:

```
import pandas as pd
from win32timezone import TimeZoneInfo
from pywintypes import TimeType
x = TimeType(2012,12,1,0,0,tzinfo=TimeZoneInfo('GMT Standard TIme'))
y = pd.Timestamp(x)
print(y)
y.tzinfo
y.utcoffset()
y.to_datetime64()
y.to_datetime()
```

This occurs with Anaconda installed win64 Python 3.4.3 and Pandas 0.16.2.

I'm going to see if I can't dig down to find a key source of failure. Stay tuned
