Test case for two interface bugs

An effect that does more than one thing concatenates the descriptions.
The effect description isn't updated when a new weapon which it affects
is added to the unit.

data/scenario-test.cfg

@@ -284,6 +284,16 @@ Xu, Xu, Qxu, Qxu, Ql, Ql, Ql, Xu, Xu, Xu, Xu, Xu, Xu, Xu, Xu, Gg, Gg, Gg, Gg, Gg
                         [/defense]
                     [/effect]
                 [/trait]
+                [trait]
+                    id=overpowered
+                    name= _ "overpowered"
+                    availability=musthave
+                    [effect]
+                        apply_to=attack
+                        increase_attacks=1
+                        increase_damage=1
+                    [/effect]
+                [/trait]
             [/modifications]
         [/unit]
         [unit]