Add snap parameter to gc object and pass it all the way to Agg.
added mdehoon's native macosx patch
Fix tick alignment in colorbars.
suppress gcc-4.3 warnings
Remove one-pixel offset in clipbox code.
Fix disappearing small markers problem.
raise on out of range text location in backend agg
reverted a bug I introduced when toying around with copy region in agg
added some helper functions for poly collections and masked regions
Added missing include, fixed debian bug #505618
