#24 Texture Atlas : experimental WIP

WIP on Texture Atlas classes
- TextureAtlas : represents a texture ( atlas ) corresponding to an
object
- TextureAtlasRenderer : represents a class which is able to render the
world position of an object into a corresponding Texture Atlas
- TextureAtlasVertexGenerator : represents a class which is able to
generate a set of vertices for every valid texel of a texture atlas ( to
be used for voxelization )