Fixed a place where md2_viewer was needlessly loading a Font from the old directory
(ie from back when i had fonts in source control ie the day before yesterday) that
it wasn't going to use anyways.  This was causing a segfault because it couldnt load
the font
Added support for compressed Targa's to gleam's Image class and converted
mp/data/font.tga back to a compressed targa
Gave gleam::Image a copy constructor and fixed a memory leak in which it
was not deleting its OpenGL texture object from the destructor like it
should have been.
got rid of that stupid background image thing
gleam::Image no longer manages the texture object for its users.
This is because it was making code less flexible by not allowing users
to set texture parameters to whatever they like, because it will be helpful
when I replace mp::Image with gleam::Image (mp::Image does not manage
textures) and because managing OpenGL state does seem a little out of
the scope of something which is only supposed to represent an image
in memory.

Also I renamed some of the member sin gleam::Image to match my newer conventions.

I also got rid of a few unused API's when it seemed like it wasn't worth the effort
to port them over to work with the changes I made to gleam::Image (for example,
gleam::TileSet::draw_clipped has finally gone the way of the dinosaurs).