Undo does not work

[brotherS]

Does not work here I addd a frame that was too big - and Undo could do nothing... I tried to draw an arrow - Undo didn't work for that either...

[mouser]

undo need some improving - most things regarding resizing and border can be undone, BUT
adding and moving objects aren't currently handled by undo - i am going to try to fix that but cannot garantee.  you can of course remove frames and delete objects, etc.