'Invert' when Updated appears

[ColinM]

Presently in order to mark a Download as 'updated' as well as the actual modification one also has to set the "Has it been 'Updated' " field to Yes.

There have been querries by several users that their Download does not show as updated because they have not set that field.
A more automatic scheme would be to 'invert' the action to say mark as not updated when modifying a Download. 

This would need another Option in either the 'Pictures and Button' tab or the 'Frontend' tab to set the Download as Modified automatically if it is changed or requires setting the "Has it been 'Updated' " field.

Colin