FF: Implement the Undo system used in IE

[FredCK]

The undo system present on browsers through execCommand is quite limited, as it doesn't take care of DOM modification (done by many features in the editor).

For IE, we have implemented a custom undo system which takes snapshots of the document area innerHTML.

The porting to Firefox is just a matter of testing and doing the necessary adjustments.

[alfonsoml]

#420 has been marked as dup

[roberto85]

so that means that the undo for the style is working only in ie , because of the Undo system , so i need to make the changes in _source/internals/fckundo_gecko.js similar to fckundo_ie.js ,

question: why if i changed the font size or the family the undo is working in FF can't u make something similar

regards thanks

[martinkou]

I've ported the undo/redo logic from fckundo_ie.js to fckundo_gecko.js. You can now perform undo styles by the undo button on the toolbar. Undoing and redoing by Ctrl-Z and Ctrl-Y are not working, yet.

[martinkou]

I'm merging this ticket to #915, the new ticket covers more critical bugs than this one.