fix zorder in root2matplotlib.hist
PEP8
fix fill style and edge color for hatched histograms
fix hatch direction
Merge pull request #364 from ndawe/zorder

MRG: fix zorder, hatch, and fill in root2matplotlib.hist
Merge pull request #365 from ndawe/master

MRG: alias Hist as Hist1D and add __all__ to plotting.hist