(Possibly) fix invisible bosses.

Unsurprisingly, MobArena's monster handling is sub-optimal, possibly
due to premature optimization. Before, when e.g. a Creeper boss would
explode, it would not be removed from the bosses collection, and thus
the ability thread would continue on running.

This patch adds a tiny bit of overhead w.r.t. removing dead monsters,
but it fixes the issue with Creeper bosses, and with a bit of luck,
mcMMO will not cause issues anymore (yet to be tested).

src/com/garbagemule/MobArena/ArenaListener.java

@@ -314,7 +314,8 @@ public class ArenaListener
         if (!monsters.getMonsters().contains(event.getEntity()) && !arena.getRegion().contains(event.getLocation(), 10))
             return;
 
-        monsters.removeMonster(event.getEntity());
+        // The generic remove method removes bosses as well
+        monsters.remove(event.getEntity());
 
         // Cancel if the arena isn't running
         if (!arena.isRunning()) {

src/com/garbagemule/MobArena/MASpawnThread.java

@@ -235,7 +235,7 @@ public class MASpawnThread implements Runnable
             }
 
             if (e.isDead() || !region.contains(e.getLocation())) {
-                monsterManager.removeMonster(e);
+                monsterManager.remove(e);
                 e.remove();
             }
         }
@@ -248,10 +248,6 @@ public class MASpawnThread implements Runnable
                 continue;
             }
             
-            // TODO remove debug message
-            Location l = p.getLocation();
-            System.out.println("Player: " + p.getName() + " found at location:" + l.getX() + ", " + l.getY() + ", " + l.getZ());
-            
             Messenger.tellPlayer(p, "Leaving so soon?");
             p.getInventory().clear();
             arena.playerLeave(p);

src/com/garbagemule/MobArena/MonsterManager.java

@@ -59,6 +59,19 @@ public class MonsterManager
         }
     }
     
+    public void remove(Entity e) {
+        if (monsters.remove(e)) {
+            sheep.remove(e);
+            golems.remove(e);
+            pets.remove(e);
+            suppliers.remove(e);
+            MABoss boss = bosses.remove(e);
+            if (boss != null) {
+                boss.setDead(true);
+            }
+        }
+    }
+    
     public Set<LivingEntity> getMonsters() {
         return monsters;
     }

src/com/garbagemule/MobArena/waves/BossAbilityThread.java

@@ -38,6 +38,9 @@ public class BossAbilityThread implements Runnable
         if (bosses.isEmpty()) {
             return;
         }
+        for (MABoss boss : bosses) {
+            if (boss.isDead()) return;
+        }
         
         // Get the next ability in the list.
         Ability ability = abilities.get(counter++ % abilities.size());