Add support for Amonkhet Mechanics

and fix some cards.
Added exerted trigger, event and add removemc keyword inside transforms
ability so we can soft code Embalm and Eternalize...

projects/mtg/include/WEvent.h

@@ -205,6 +205,12 @@ struct WEventCardCycle : public WEventCardUpdate {
     virtual Targetable * getTarget(int target);
 };
 
+//event when card is exerted.
+struct WEventCardExerted : public WEventCardUpdate {
+  WEventCardExerted(MTGCardInstance * card);
+    virtual Targetable * getTarget(int target);
+};
+
 //Event when a card's "defenser" status changes
 //before : attacker that card was blocking previously
 //after: attacker that card is blocking now