Added OBJ export

The UI isn't there yet (I just didn't get around to yet; it exists, but
isn't being set as the delegate properly). Other than that, the export
works, although I'm not sure about the file paths - they certainly
confuse Wings.
Added view controller for export, and fixed a bug (textures still aren't shown properly, though).
Add material library to obj file.

That way, it will export correctly.
Merge branch 'master' into lion

Conflicts:
	GLLara.xcodeproj/project.pbxproj