matplotlib Code

Still trying to fix compile error on 64-bit platforms...

Fix compile error on 64-bit platforms.

Fix compilation error on 64-bit platforms.

Speed up auto-legend.

Speed improvements.

New path-related utilities (used for an aborted attempt at fixing
contouring -- may be useful in other contexts in the future).

Update to use modern Numpy C API

Further speed improvements. For collections, now has faster ignoring
of elements that aren't provided, such as offsets. Paths now do not
even store the "default" codes array -- which is MOVETO followed by N
LINETOs. These are generated automatically by the iterators if no
codes array is provided. (Should also result in significant memory
savings for graphs with many points.)

Forgot to svn add these files in last commit.