Add function to check for an OpenGL extension.
Fix unittest.
Add unfinished yet worthy ENet wrapper from Kelet. Thanks!
As an experiment, this wrapper does not require manual library loading like other GFM wrappers.
[ENet wrapper] Fix imports to suit GFM module naming.
gfm.enet officially advertised in documentation index.
Merge branch 'master' of https://github.com/p0nce/gfm

Conflicts:
	math/gfm/math/funcs.d