Broken history for colored nets

[Jiri Srba]

Open the colored philosophers example net.
Remove all five tokens from the place fork.
Undo the change (ctrl-Z).
Now edit the tokens in place fork and modify the 1'id1 to 2'id1 (add one more token of id1).
Press OK and you get the following:

Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: Type mismatch: Attempted to put Id2 in multiset of type Philo
 at dk.aau.cs.model.CPN.ColorMultiset.put(ColorMultiset.java:61)
 at dk.aau.cs.model.CPN.ColorMultiset.add(ColorMultiset.java:112)
 at dk.aau.cs.model.CPN.ColorMultiset.addAll(ColorMultiset.java:123)
 at dk.aau.cs.model.CPN.Expressions.AddExpression.eval(AddExpression.java:47)
 at pipe.gui.petrinet.editor.PlaceEditorPanel.doOkColors(PlaceEditorPanel.java:743)
 at pipe.gui.petrinet.editor.PlaceEditorPanel.doOK(PlaceEditorPanel.java:693)
......