msdftext usage

[JaoSchmidt]

The texture rendering is pretty much finished, but a couple of coding need to be done before calling it complete:

• The msdftext isn't rendering properly except with opensans and arial with emSize = 40. Need to figure out why that's the case.
  This can be seen when drawing a simple square with a atlas texture, other fonts will aprear deformed.

The game engine doesn't allow for textures to be deleted.

• the allocateTextures does not deal with removed textures
• the allocateTextures isn't dealing with Maximum Texture Units (MTU), which is the hardware limit for number of binded textures in a single shader. A proper flushing need to be done when reaching the limit
• also, every buffer does not have limit, therefore a limit must be detected and flushed
• the allocateTextures is being called at every draw that require textures, perhaps this can be made a little more performant (probably a good idea to solve this last)