- restored default one 'solid' light

- subsurd level '0' is possible again.
  however; it was changed to '1' because convert-to-mesh crashes. the
  subsurf code doesnt give a result when level is '0', causing the convert
  routines to either crash, or deliver empty mesh...
  I added a warning in the convert routine now, and dont do anything then.
- changed all glFlush() in glFinish() in editobject.c, which seems to be
  the right magical call to show frontbuffer drawing.

source/blender/src/editobject.c

@@ -1689,7 +1689,10 @@ void convertmenu(void)
 			else if(ob->type==OB_MESH) {
 				Mesh *oldme= ob->data;
 				
-				if (oldme->flag&ME_SUBSURF) {
+				if( oldme->subdiv==0 ) {
+					error("No subdivision Mesh to convert available");
+				}
+				else if (oldme->flag&ME_SUBSURF) {
 					ob->flag |= OB_DONE;
 
 					ob1= copy_object(ob);