matplotlib Code

doc updates

using exiting examples rather than new pyplot ones for screenshots

added mpl CSS style file

Improve docstrings in nxutils

Change nxutils.points_inside_poly to return an array of bool, not int.

replaced index with contents for main page

removed defunct colours mod

added sidebar for web docs

preparing to move entire web site to sphinx; things may be whacked for a day or so

fixed data file in rec group by example