Expose nd::arrfunc through the cython layer
Use static instances for date/time/datetime types as well
Make the arrfunc wrapper class a subclass of array
Renamed instantiate_func to instantiate in arrfunc structure
Add __call__ to the arrfunc wrapper object
Change make_rolling_arrfunc to generate proper funcproto
Switch the rolling tests to use the call operator on the arrfunc
Remove top-level imports
Expose mean1d in the nd namespace
Merge pull request #85 from mwiebe/expose_af

Exposure of nd::arrfunc to python