Add back some of the progressive mesh patch that was lost in the merge.
Add back some of the progressive mesh patch that was lost in the merge.

paroj/ogre,RealityFactory/ogre,RealityFactory/ogre,OGRECave/ogre,OGRECave/ogre,OGRECave/ogre,RealityFactory/ogre,OGRECave/ogre,paroj/ogre,paroj/ogre,paroj/ogre,RealityFactory/ogre,paroj/ogre,OGRECave/ogre,RealityFactory/ogre