matplotlib Code

Trivial bugfix to eliminate IndexError

added bang header to examples

* Fixed embedding_in_wx and dynamic_demo_wx examples

* Ported build to darwin

* Tk:

removed default figman=None from nav toolbar since it needs the
figman

fixed close bug

small changes to aid darwin build

Added the "numerix" Numeric/numarray selector module enabling matplotlib
to work with either numarray or Numeric. See matplotlib.numerix.__doc__.

First version of dynamic_demo for backend_wx