render large fonts using triangulated outline

[sidorares]

If bitmapped glyph data is larger than trianulated mesh it's better to use trangles instead of CompositeGlyph. Prob use some heuristic like "typically under 60x60 pixel raster glyphs, over -> vector". Need to collect example average packet sizes for sample fonts

https://github.com/mattdesl/fontpath/blob/master/lib/SimpleJson.js