Make main.py executable
Multiple compile error and warning fixes
Add extension and version detection to GLX loader
Add support for wgl extension lookup
Make header look a little better
Protect windows.h inclusion, as it doesn't do so itself
Honor <apientry/> xml tag in callback types
Make it possible for GLAD to be used as a shared library
Merge pull request #7 from BtbN/master

Numerous fixes to glx and wgl C generation