Undo does not work when moving nodes with the arrow keys

[Francisco Javier Díez]

Nodes can be moved by selecting them and using the arrow keys, but (unlike moving the nodes with the mouse) this operation cannot be undone.

[Jorge Pérez]

See method keyPressed (line 2541) of the EditorPanel class. To transform the action into an undoable edit, it is needed to perform some changes on the MoveNodeEdit class, which manages the action of moving nodes with the mouse (maybe an overload of the constructor is enough).