Wrapped library inside a namespace, to avoid name
collisions.
Added documentation for the macros avaliable to customise
the library. Will remove `LIBROCKET_MAGNUM_CREATE_SHADER`.
Wrapped all code within a namespace (implementation)
Updated code to (hopefully compile)
Using Vector2ui instead of Vector2 to store size
Removed creation of shader, since that's quite inflexible
Added license to headers
Updated LICENSE
Updated info in README