matplotlib Code

Added the ability for the following in the various GUI backends:
>>> import pylab
>>> fig = pylab.figure()
>>> fig.canvas.set_window_title("My Plot Window")

Add svgz support to backend_svg and backend_cairo.
Put all styles inside of a separate <style> element in backend_svg, to
save considerably on file size.

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.

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.

Add valignment = 'baseline' feature to align text by its baseline.

Use regular expressions to do dedenting. This is ~15X faster than the
old implementation. dedent accounted for around 30% of the time spent
in "import pylab", so was probably worthy of optimization, even if this
regex approach is less clear. The results are identical to the old
implementation, with the exception of a single docstring (in
backend_bases.py) that needed to be fixed.

Allow application to remove artists from the axes

Numpification new try: dont touch numerix/, but make mpl code independent of it.
(Including conversion to "import numpy as npy")
Complete except for pylab.py and mlab.py

reverted numerix breakage, with apologies

completed numpification of most trivial cases