Series.max() returning Series instead of single element when dtype == timedelta64
When selecting the max() of a Series containing timedelta64, the return value is a Series with a single element, instead of the element itself:

In [1]: pd.**version**
Out[1]: '0.14.1'

In [2]: np.**version**
Out[2]: '1.9.0'

In [3]: from numpy.random import randn

In [4]: s = pd.Series([np.timedelta64(int(x), 'us') for x in randn(10)*1e6])

In [5]: s.dtype
Out[5]: dtype('<m8[ns]')

In [6]: s.max()
Out[6]:
0   00:00:01.275209
dtype: timedelta64[ns]

In [7]: type(s.max())
Out[7]: pandas.core.series.Series
