Separated LL functions
Created by: VLanvin
Seems OK for merging.
- Most modules now have an "LL" submodule where low-level functions are encapsuled.
- OgamlCore.Core has been renamed in OgamlCore.LL
- OgamlGraphics.Internal has been renamed in OgamlGraphics.GL (not LL, to avoid name clashes)
- Internal-only enumerations of Enum.t have been moved to GL.Types
- Exposed enumerations of Enum.t have been moved to separated modules