Improved docstrings in colors.py
Use autoscale_view for contour plot autoscaling
Fixed all Gtk memory leaks exercised by D2Hitman's recent thread.
Further memory leak fixes for Gtk
Reduce memory leakage in Gtk+-based backends. Still far from perfect.
Turn off mixed-mode rendering when svg.image_noscale is True.
Fix minor bug in findfont -- None input should return default font.
First pass formatting dates.py documentation.
patches: use None rather than 0 for full wedge
patches: allow partial rings with Wedge
