bug 1066043 - split gfxFont.cpp and .h into more manageably-sized pieces. r=jdaggett

--HG--
rename : gfx/thebes/gfxFont.cpp => gfx/thebes/gfxFontEntry.cpp
rename : gfx/thebes/gfxFont.h => gfx/thebes/gfxFontEntry.h
rename : gfx/thebes/gfxFont.cpp => gfx/thebes/gfxGlyphExtents.cpp
rename : gfx/thebes/gfxFont.h => gfx/thebes/gfxGlyphExtents.h
rename : gfx/thebes/gfxFont.cpp => gfx/thebes/gfxTextRun.cpp
rename : gfx/thebes/gfxFont.h => gfx/thebes/gfxTextRun.h