matplotlib Code

Refactoring of FigureCanvas*.print_figure so that each backend does
not have to track all other possible filetypes. This should make it
easier to add new filetype backends without updating lots of places.
All GUI backends have the same base set of filetypes they support,
defined in FigureCanvasBase. Non-GUI backends, for the most part will
still only write to their own file format (and not do any
switch_backend magic.) All GUI backends (where possible) now generate
a list of file patterns for their file chooser dialogs, rather than
having hard-coded lists.

See FILETYPES for matrix of filetypes supported by each backend.

Small bugfix in pdf backend

Undoing last commit. I don't understand why a gray8 buffer is four
bytes per pixel, but there's a lot I don't understand about Agg.

Fix set_name call.

Fix get_xyz_where() typo so spy_demos works again

Convert to numpy

fixed some minor bugs related to mathtext: text
markup in new config, uncommented print statement

Bugfix #1671570: Invalid CSS 2 styles in SVG output

Fix some recent reference counting bugs in ft2font.cpp (Thanks to Paul Kienzle).

Bugfix #1767997: Zoom to rectangle and home, previous, next buttons

The "original" position of the axes was not being saved/restored in
the history stack. This patch saves both "original" and "active" position.