ANN: matplotlib-0.70

This is (hopefully) a final rollup of what is (should be) a fairly
stable tree. Mainly I wanted to send a release notification out to
the larger python community (scipy/numpy/python-list) since I haven't
done that since 0.60 (July 2004).

For the major releases, I tend to try and shy away from new features
preferring a stable src. But for you hardened, grizzled matplotlib
veterans, there are a few enticements nonetheless

- pie charts and new example/pie_demo.py. See
   http://matplotlib.sf.net/screenshots.html#pie_demo

- support for object picking - see examples/picker_demo.py. As
   people test this out and we settle on an interface, this will
   probably become part of the core, as will other keypress
   functionality for navigation, grid toogle, zoom toggle etc.

- Fixed coords notification in wx toolbar

- key press and release event supported across backends -- see
   examples/keypress_demo.py

- added Shadow patch class to provide a shadow effect for polygons,
   legends, pie charts -
   http://matplotlib.sf.net/screenshots.html#legend_demo

- new examples/text_rotation.py demonstrates how text rotations and
   alignment work in matplotlib.

Bug fixes

  - Fixed PS mathtext bug where color was not set

  - Fixed an agg text rotation alignment bug, fixed some text kwarg
    processing bugs

  - Refactored event handling - multiple connects and disconnects now
    work across backends. See examples/coords_demo.py, especially
    with test_disconnect

  - Fixed a tkagg interactive bug that caused segfaults in some
    conditions.

As usual, downloads at http://sourceforge.net/projects/matplotlib

JDH