matplotlib-py3: dateutil 2.0 and patch for mathtext_wx example

Hello,

Dateutil 2.0 is now available for Python 3.x at <http://niemeyer.net/python-dateutil>.

The example user_interfaces/mathtext_wx.py is broken since as_rgba_str() was removed from the ft2font extension. A patch is attached.

Christoph

mathtext_wx.diff (1.19 KB)