Undo and redo history
          The undo/redo history is held on a per-form-window basis, up to a user-definable maximum number of actions.
         
         The default is 20.
These actions are supported by the Undo/Redo History feature:
- Control creation
 - Control deletion
 - Form window property modification (via the property browser or via resize)
 - Change control type
 - Control reparenting
 - Tab page/grid column reordering
 - Tab order changes
 - Form permission changes
 - Form help changes