It should work now that arm memset() has been fixed for negative
values. This is the last puzzle that was disabled due to a crash.

Both these puzzles now have long press mapped to spacebar.

This lets puzzles remember which fonts were loaded previously so
they can be preloaded when the puzzle is started (and the disk is
spinning), instead of while the game is being played.

Sure beats typing on the virtual keyboard.

Add an option to visualize polygon rendering to aid in diagnosing
artifacts.

Yet another workaround to accomodate our polygon
drawing "algorithm" (if you can call it that).

- change point ordering to make concave polygon rendering work
- also enables an "Easter egg" of sorts

Change-Id: I3b4044a374dce1cff889d5f3744de9e634978591

Up to now, we'd just ignore whatever font size the puzzle asked for,
and instead just go with either the UI font or system font regardless
of their size, which led to some horrible-looking puzzles. This patch
adds the ability to automatically load fonts of the proper size when
they are available, which makes text-based puzzles such as Pattern and
Slant function correctly with any UI font.

The font pack, which should be extracted to the system-wide fonts
directory consists of 3 small bitmap fonts from 7px to 10px and then
anti-aliased Deja Vu fonts from 10px to 36px. It is available in the
source tree (apps/plugins/puzzles/fonts.zip), or from
<http://download.rockbox.org/useful/sgt-fonts.zip>.

Change-Id: I05c8fe7bd6d867e14de9b941deb91e8c642ee4a8