When rendering text, if none of the fonts in the cascade list contain a
glyph for a given code point, we now query Skia's font manager to find
a system font that can render it.
this commit also introduces GlobalFontConfig class that is now
responsible for fontconfig initialization. it seems sane, even thought
FcInit's docs state that if the default configuration has already been
loaded, this routine does nothing.
the goal is to rely on fontconfig for font directory resolution. it
doesn't seem like it would be appropritate to call to fontconfig funcs
from within the LibCore.
i'm not 100% confident that FontDatabase is the correct place.. seems
okay?
