BUG: Timedelta * Series -> TypeError
I encountered this today when rerunning a script that worked prior to the 0.15 arrival of Timedelta:

```
In [2]: pd.to_timedelta(10, unit='D') * pd.Series(range(10))
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-2-a5e3bc3be480> in <module>()
----> 1 pd.to_timedelta(10, unit='D') * pd.Series(range(10))

/Users/shoyer/dev/pandas/pandas/tslib.so in pandas.tslib.Timedelta.__mul__ (pandas/tslib.c:31355)()

TypeError: cannot multiply a Timedelta with <class 'pandas.core.series.Series'>
```

@jreback I think there might be another issue for this already?
