Fixed conversion and deprecated API warnings on Mac OS X.

Replaced Apple-specific code with new one, as suggested in
https://bitbucket.org/alfonse/glloadgen/issue/29/compilation-errors-on-mac-os-x
Hopefully this won't introduce any new issues.
Added .kateconfig.

Tabs, tabs everywhere.
Spec drop from SVN: 24596.

README about how to do this will follow.
Added README explaining what the fork.
Merge branch 'updated' into magnum