Major update to LWO loader to support more material properties and work with more meshes. Changed some meshloader constructors to take scenemanager instead of other parameters. Fixed obj loader texture loading with mixed file separators.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@1215 dfc29bdd-3216-0410-991c-e03cc46cb475