Add Font rendering

[SnowyCoder]

Rendering optimizations:
String batching + caching (read comments): https://www.reddit.com/r/Minecraft/comments/3ek0o7/why_text_rendering_is_horrible_how_it_can_be/

[SnowyCoder]

Other resource: https://en.wikibooks.org/wiki/OpenGL_Programming/Modern_OpenGL_Tutorial_Text_Rendering_02