Combine two watches on stSafeSrc to prevent calling updateSafeCopy twice

When using the stSafeSrc attribute and data is loaded through an AJAX call, both watches in stTableController are triggered. Both watches are in place to insure that safeCopy is updated. As a result function updateSafeCopy is called twice when data is loaded through an AJAX call. This effect is easily remedied by combining both watches in a $watchGroup.