draw_text and draw_tex w/ textpath

Hi,

The backend_base in the trunk now has the draw_text_as_path method
which draws the text using the textpath module. The draw_text and the
draw_tex method calls it by default. This will enable a primitive
support for text and tex for all the backend which implements
draw_path method. This should not affect the functionality of existing
backends. The draw_text_as_path in the backend_base is a very basic
implementation. It simply calls draw_path for rendering. A special
version of the draw_tex method for the svg backend is implemented,
which caches the glyph paths of characters to reduces the output size.

So, here are examples.

usetex w/ svg backend : http://dl.getdropbox.com/u/178748/mpl/tex_demo.svg

text with html5 canvas backend : http://dl.getdropbox.com/u/178748/mpl/test.html

Well, the quality of the rendered text is not best, but seems good
enough for me.
Regards,

-JJ