add GNU FreeFont for some rare charactors like phonetic symbols
add glyph fallbacks
if glyph is not found in specified fontface, fallback fonts are checked
on by one until a glyph is found.
add 'make fonts' command that merges additional fonts in resources into fonts pool
rm additional fonts in resources dir in customupdate
Merge pull request #124 from chrox/glyph_fallback

add glyph fallback