Speed up enum code generator

Scan through the list of wrappers once, instead of multiple times, in
order to find out which functions use which enums. This speeds up enum
generation tremendously.
Added int/uint to the c# typemap
Cleaned up ending trim regex

Trim regex will now correctly match GetInteger64 and other functions
ending in "64". It also uses a correct ending anchor to avoid matches
in the middle of a function name.
OpenGL overrides for compatibility

Added overrides to maintain backwards compatibility with
OpenTK.Graphics.OpenGL.GL. These were generated
through the apitest tool.
Regenerated bindings