Do not clear selection during operations that don't need it.

Specifically, during "Align View onto Workplane" when we are locked
in workplane (in which case it always aligns onto that workplane).

src/graphicswin.cpp

@@ -506,7 +506,6 @@ void GraphicsWindow::MenuView(Command id) {
         case Command::ONTO_WORKPLANE:
             if(SS.GW.LockedInWorkplane()) {
                 SS.GW.AnimateOntoWorkplane();
-                SS.GW.ClearSuper();
                 SS.ScheduleShowTW();
                 break;
             }  // if not in 2d mode fall through and use ORTHO logic