Fix issue #473 and #784

It seems when a zonechange event from inplay to inplay (player or
opponent), the card->view item values is recalculated... so it destroys
the GUI like missing card image, or moving it far off the screen... To
reproduce, cast Splinter Twin to Conquering Manticore and gain control
the same creature about 2 or 3 times...

projects/mtg/src/WEvent.cpp

@@ -165,6 +165,11 @@ WEventCardUnattached::WEventCardUnattached(MTGCardInstance * card) :
 {
 }
 
+WEventCardControllerChange::WEventCardControllerChange(MTGCardInstance * card) :
+    WEventCardUpdate(card)
+{
+}
+
 WEventCombatStepChange::WEventCombatStepChange(CombatStep step) :
     WEvent(), step(step)
 {
@@ -319,6 +324,12 @@ Targetable * WEventCardUnattached::getTarget(int target)
     return NULL;
 }
 
+Targetable * WEventCardControllerChange::getTarget(int target)
+{
+    if (target) return card;
+    return NULL;
+}
+
 std::ostream& WEvent::toString(std::ostream& out) const
 {
     return out << "EVENT";