[9734] - See http://tracker.modx.com/issues/9734
Disable save button when there is no change in the grid
[#9734] Fix save button state on Content Types grid

Merge remote-tracking branch 'rtripault/fix-9734' into release-2.2

* rtripault/fix-9734:
  [9734] - See http://tracker.modx.com/issues/9734 Disable save button when there is no change in the grid