GL 3.2 bindings

Inclusion of 3.2 makes gogl more useful on OSX

OSX version:   GL:
Snow Leopard   2.1
Lion           3.2
Mountain Lion  3.2
Mavericks      4.1
Merge pull request #31 from lloeki/master

GL 3.2 bindings
Update documentation links in README.mkd
Merge pull request #33 from garyburd/patch-1

Update documentation links in README.mkd