Fix stupid mistake with Major/Minor hints

o_o
Merge pull request #133 from bjz/fix-hints

Fix stupid mistake with Major/Minor hints
Add documentation regarding OpenGL on OS X
Merge pull request #134 from bjz/osx-hint-docs

Add documentation regarding OpenGL on OS X
Enabled get_###_version()
Merge pull request #135 from ozkriff/master

Enabled get_###_version()
Rewrite error and monitor event callback API
Add an example that demonstrates custom error callbacks
Update examples
Merge pull request #136 from bjz/callbacks

Rewrite error and monitor event callback API
Fix callback setter docs
libc is now a separate crate
Merge pull request #137 from bjz/docs

Fix callback setter docs
Merge pull request #138 from bjz/libc

libc is now a separate crate
Changed build to make it work in my own project.

I need to link it statically and I don't really see a way to do it
without hacking the way it's built.