Fix empty dataframe partitioning for numpy 1.10.4 (#2862)
Fix empty dataframe partitioning for numpy 1.10.4 (#2862)

This was failing, as numpy 1.10.4 checks for `'NaT'` casting failed.
Rewritten to just try to create a missing value, and fallback to `NaN`.
dask/dask,blaze/dask,dask/dask,jcrist/dask,jakirkham/dask,mrocklin/dask,ContinuumIO/dask,mrocklin/dask,jcrist/dask,jakirkham/dask,ContinuumIO/dask,blaze/dask