matplotlib Code

Fix placement of rotated text in Wx backend (thanks Michael Day).

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

Build the path module (inadvertently removed during a merge).

Update to use new numpy macros.

Fix alignment of clipping rectangles.

Fix bug in PDF backend.

further refinement of GEOS library version checking

more tweaking of error messages.

clearer error message if wrong version of GEOS found.

Use mpl standard import idiom in image.py