This commit integrates the bitmap font in the resource system, so
that cross-compilation would be easier.
The font handling code was carefully written to do glyph parsing
lazily; in practice this means that after this commit, startup
is less than 25ms slower, most of it spent in inflate().
This should also result in faster rendering, since there is no
rampant plane switching anymore; instead, all characters that are
actually used are stashed into same one texture.
whitequark