Removed all references to platform specific code in the data and abstract classes.

Adds Color class, which wraps Vector4 with utility methods.
Adds GL class for some enumerated GL int value mappings to prevent arbitrary magic numbers.
Enums which are only composed of the GL int value are not in the GL class, they are simply wrapped by the Enum.

Signed-off-by: Nick Minkler <sleaker@gmail.com>