Moved emission of ElementDeleteEvent till after the relaltionships are unkinked.

Now when undoing/redoing, the order of events in correct and reproducable.

gaphor/UML/element.py

@@ -92,10 +92,10 @@ class Element(object):
         """
         # Uses a mutex to make sure it is not called recursively
         if self.__in_unlink.testandset():
-            component.handle(ElementDeleteEvent(self._factory, self))
             try:
                 for prop in self.umlproperties():
                     prop.unlink(self)
+                component.handle(ElementDeleteEvent(self._factory, self))
             finally:
                 self.__in_unlink.unlock()