Properly fixed the OpenGL extension search. Also removed the glu part in order to get rid of glu at all.
Added a Linux keyboard fix posted by denton. Now, Linux also sends just KeyPressed for Autorepeat, instead of alternating KeyReleased-KeyPressed.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@882 dfc29bdd-3216-0410-991c-e03cc46cb475