Mesh drawing stuff!

- in zbuffer mode, vertices will be blended 50% in... and when you increase
  vertex size larger than 2 pixels, it will draw them smaller
- removed all 'wire extra' calls (there were dozens!) and replaced it with
  simple call where it belongs.
  This drawing mode is becoming nice & stable... maybe something to make
  default on for new objects? Makes selecting quite easier...

- Subsurf: in editmode, with new 'Optimal' option set, the mesh itself
  will not draw, but instead it draws 'handles' to the vertices. Looks
  extremely clean!

- matched drawing of default grid-floor (persp) to ortho grid

- killed drawing vertices outside of main drawing loop, apart from the
  routine that uses mouse-selecting. (tekenvertices_ext()). It was an old
  optimize routine which became quite useless.

source/blender/src/buttons_object.c

@@ -935,7 +935,7 @@ void do_common_editbuts(unsigned short event) // old name, is a mix of object an
 					}
 					evl= evl->next;
 				}
-				tekenvertices_ext( event==B_MATSEL );
+				allqueue(REDRAWVIEW3D, 0);
 			}
 			else if ELEM(G.obedit->type, OB_CURVE, OB_SURF) {
 				nu= editNurb.first;