Timestamp handles a different date range than datetime.datetime and numpy.datetime64
This may very well be known/intentional, and if so I think it's worth putting in doc somewhere. 

```
>>> datetime(2300,1,1)
datetime.datetime(2300, 1, 1, 0, 0)
>>> numpy.datetime64('2300-01-01')
numpy.datetime64('2300-01-01')
>>> Timestamp('2300-01-01') # pandas.tslib.OutOfBoundsDatetime

```
