ddof no longer passed for Series.std and Series.var

[dalejung]

As part of the following commit:

fbb1102#L5L799

Series.std and Series.var no longer pass along ddof to the nanops.nanvar function.

Also since ddof defaults to 1 in pandas and 0 in numpy.

arr = np.arange(10)
s = Series(arr)
# False
np.std(s) == np.std(arr)
# True
np.std(s) == np.std(arr, ddof=1)

Which I don't know if it's a bug but it's non-intuitive.

[wesm]

fixed in PR #965 (will be part of pandas 0.7.3)