Fix 'Preferred Family' and 'Compatible Full' SFNT entries.

This should fix the issues with Ligalex and Ubuntu Mono Ligaturized colliding
with the original fonts in some font selectors.

Generate font type corresponding to input font

Remove output-fonts in favour of releases

Ligaturized fonts are no longer checked in; instead they're zipped and
put under releases.

Completely rework build process, and rename files for license compliance

This addresses ToxicFrog#25 and (partially) ToxicFrog#42; fonts that we can't make derivative
works of are no longer checked in, and fonts that need to be renamed for
license compliance have been.

The build process is also now a bit more robust.