Bug 280443 p1 - define struct for font family lists. r=roc
Bug 280443 p2 - parse font family lists into fontlist structs. r=heycam
Bug 280443 p3 - use fontlist struct in gfx. r=roc,fredw
Bug 280443 p4 - properly escape unquoted font family names. r=heycam
Bug 280443 p5 - fixup problem with MathML stretchy fallback. r=fredw