This enables Rockbox to render anti-aliased fonts using an alpha blending method.
The input font bitmaps are 4bit, i.e. 4x larger, but the metadata size stays the same.
A tool, convttf, for converting ttf fonts directly to the Rockbox fnt format is provided.
It has a useful help output, but the parameter that works best is -c1 or -c2 (2 for larger font sizes).
Flyspray: FS#8961
Author: Initial work by Jonas Hurrelmann, further work by Fred Bauer, Andrew Mahone, Teruaki Kawashima and myself.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29523 a1c6a512-1295-4272-9138-f99709370657