- update displistmesh_to_mesh to free existing mesh data (including

sticky, dvert, and keys if number of verts don't match)
 - changed modifier panel to not allow manual addition of hook or
   softbody modifiers
 - changed apply modifier to apply to existing mesh (fixes bug with
   materials) and to warn about loss of tface/mcol/keys/dvert/sticky
   for all modifier types
 - changed modifier UI to not display disclosure triangle for virtual
   modifiers
 - changed softbody ui to allow enable/disable

source/blender/src/editobject.c

@@ -2223,7 +2223,6 @@ void convertmenu(void)
 				dm= mesh_create_derived_no_deform(ob, NULL);
 				dlm= dm->convertToDispListMesh(dm, 1);
 				displistmesh_to_mesh(dlm, ob1->data);
-				displistmesh_free(dlm);
 				dm->release(dm);
 			}
 			else if(ob->type==OB_FONT) {