Modify Revision History (revisionDialog.html) for specific ItemTypes

Hi Chris, thank you for testing this in your system! I wouldn´t been able to fix this one. With your additional code, the revision history now works as expected. I agree that changes to the codetree files without backup of the native file wouldn´t be very smart. But to share a few of my own experiences: I would also recommend to everybody to write down modifications of this kind into a separate document. Reason is very simple -> Update! Especially small code tree changes have a high risk of getting lost during update. Angela