"Undo" and "Redo" functionality.

[seb-dal]

Currently one of the most frustrating things about ArgoUML is that if you accidently make a mistake like deleting the wrong Class, it's impossible to use CTRL-Z to cancel your action and you have only 2 choises, redo every this manually or use the saveAs button after each change to be sure you don't ruine a project.

[linustolke]

I can only agree. Please work to improve this.

[LordOfTheDings]

same here