Volume Rendering: check for the Root in the ChunkHandler destructor as it might already be deleted
Volume Rendering: check for the Root in the ChunkHandler destructor as it might
already be deleted

--HG--
branch : v1-9

digimatic/ogre,digimatic/ogre,digimatic/ogre,digimatic/ogre,digimatic/ogre,digimatic/ogre,digimatic/ogre