matplotlib Code

Small cleanup of logic in handling drawstyle in Line2D

Fix clipping on collections.

devel docs: minor typo

Fix some minor typos in the paths tutorial

Fix some minor typos in the transforms tutorial

Fix some minor typos in the transforms tutorial

added looking glass demo

added path tut

Remove unmasked_index_ranges from lines.py; it is still in cbook.py

Add docstring.py; I forgot to add it when committing the Coombs patch