Improved index selection in DFrameView _export_dataviews
Added bins option to DFrameView hist plot_opts
Formatting and docstring fixes in interface module
Improved dimensions handling in DFrameView constructor
Enabled <= ndim slicing in DFrameView getitem
Fixes to DFrameView dimensions handling
Renamed and improved stack method on DFrameView
Added docstring to DFrameViewPlot style_opts