Initial pass of Exert (lots of things to be improved, but should be good enough to start scripting)

forge-gui-desktop/src/test/java/forge/gamesimulationtests/util/PlayerControllerForTests.java

@@ -221,6 +221,11 @@ public class PlayerControllerForTests extends PlayerController {
         return blockers;
     }
 
+    @Override
+    public List<Card> exertAttackers(List<Card> attackers) {
+        return Lists.newArrayList(attackers);
+    }
+
     @Override
     public CardCollection orderBlocker(final Card attacker, final Card blocker, final CardCollection oldBlockers) {
         final CardCollection allBlockers = new CardCollection(oldBlockers);