Irrlicht Engine

I submitted a rather simple patch on Sourceforge ( https://sourceforge.net/p/irrlicht/patches/296/ ) which prevents crashes when trying to load an OBJ which contains invalid indices for vertices, texture coords or vertex normals in the definition of a face.

Please consider applying this patch to Irrlicht. Thanks!

OK, I also think it's better with checks. Applied in trunk svn r4983. Thanks for the patch.