display: Use XInput2 to grab the pointer

As calling XIGrabDevice multiple times will change it, just
drop the XChangeActivePointerGrab path and just go down the
XIGrabPointer path always.

https://bugzilla.gnome.org/show_bug.cgi?id=688779

src/core/window.c

@@ -9867,9 +9867,8 @@ meta_window_update_keyboard_resize (MetaWindow *window,
   if (update_cursor)
     {
       meta_display_set_grab_op_cursor (window->display,
-                                       NULL,
+                                       window->screen,
                                        window->display->grab_op,
-                                       TRUE,
                                        window->display->grab_xwindow,
                                        window->display->grab_timestamp);
     }