Rewrite font builder tool to be much simpler and to support more text
effects.
Change GUI to use new set of fonts.
Switch font textures from TGA to PNG so they're easier for the font
builder to create.
Support RGBA font textures (for e.g. stroked text).
Greatly improve text rendering performance by using vertex arrays.
Fix rendering code leaving vertex buffers bound.
Add 'clip' property to GUI text objects, to disable clipping when
rendering.
Delete part of unused console function registration system.
This was SVN commit r7595.
