[feature] Font rendering

[karol-gruszczyk]

Fonts should be loaded using FreeType library.
Glyphicons should be stored in a single texture atlas and rendered using instanced rendering.

There be two types of Text:

• Dynamic text (all glyphicons rendered every time render call)
• Static text (glyphicons are rendered only once, after setText method, to a FrameBuffer texture, later it should use the cached text texture), currently blocked by [feature] Frame buffer implementation #2