ENH: add to_offset method to Timedelta
from [SO](http://stackoverflow.com/questions/27444949/build-a-pandas-pd-tseries-offsets-from-timedelta)

This works, but I think `td.to_offset()` makes sense

```
In [1]: td = Timedelta('1h')

In [2]: td
Out[2]: Timedelta('0 days 01:00:00')

In [7]: pd.DateOffset(hours=td.hours)
Out[7]: <DateOffset: kwds={'hours': 1}>
```
