BUG/VIS: fix Series.hist so that users can create hist subplots without the mpl API
ENH: add more informative error message when dupe style and color args are given
Merge pull request #4414 from cpcloud/fix-hist-subplots

BUG/VIS: fix Series.hist so that users can create hist subplots without the mpl API
First implementation of Stata 13 (format 117) support (untested so far)