ofTrueTypeFont: Compute initial lineHeight using font metrics instead of a guess
ofTrueTypeFont: Add ascender, descender and glyph bounding box metrics
Merge branch 'master' of https://github.com/nneonneo/openFrameworks into mergeTTFMetrics

Conflicts:
	libs/openFrameworks/graphics/ofTrueTypeFont.cpp
	libs/openFrameworks/graphics/ofTrueTypeFont.h