rename attributeIndex_c -> AttributeIndex_c
rename shape_c -> Shape_c
rectangleShape_c -> RectangleShape_c
move some bigger or rarely used functions from header to code
remove CommandData_c from inside the TextLayout_c class
include a forwarding variant of the addCommand functions

This makes code quite a bit simpler
rename fontResource_c -> FontResource_c
freeTypeLibrary_c -> FreeTypeLibrary_c
fontFace_c -> FontFace_c
fontCache_c -> FontCache_c
fontFamily_c -> FontFamily_c
glyphKey_c -> GlyphKey_c
code formatting
properly encapsulate the freetype bitmap in our own class
replace header guards by standard conformant defines
improvements to SDL glyph cache

- fix typo in name
- allow trimming of cache to a certain size
- the glyphs that were used the longes time ago are removed