Embrace diamond operator (again).

Not sure how these dodged the bullet of commit
0eeed4ff01, but here we go!

src/main/java/com/garbagemule/MobArena/ArenaMasterImpl.java

@@ -182,7 +182,7 @@ public class ArenaMasterImpl implements ArenaMaster
 
     public List<Player> getAllPlayersInArena(String arenaName) {
         Arena arena = getArenaWithName(arenaName);
-        return (arena != null) ? new ArrayList<>(arena.getPlayersInArena()) : new ArrayList<Player>();
+        return (arena != null) ? new ArrayList<>(arena.getPlayersInArena()) : new ArrayList<>();
     }
 
     public List<Player> getAllLivingPlayers() {
@@ -194,7 +194,7 @@ public class ArenaMasterImpl implements ArenaMaster
 
     public List<Player> getLivingPlayersInArena(String arenaName) {
         Arena arena = getArenaWithName(arenaName);
-        return (arena != null) ? new ArrayList<>(arena.getPlayersInArena()) : new ArrayList<Player>();
+        return (arena != null) ? new ArrayList<>(arena.getPlayersInArena()) : new ArrayList<>();
     }
 
     public Arena getArenaWithPlayer(Player p) {

src/main/java/com/garbagemule/MobArena/ClassLimitManager.java

@@ -45,7 +45,7 @@ public class ClassLimitManager
     private void initInUseMap() {
         // Initialize the in-use map with zeros.
         for (ArenaClass ac : classes.values()) {
-            classesInUse.put(ac, new HashSet<String>());
+            classesInUse.put(ac, new HashSet<>());
         }
     }
     
@@ -76,7 +76,7 @@ public class ClassLimitManager
         if (classLimits.get(ac) == null) {
             limits.set(ac.getConfigName(), -1);
             classLimits.put(ac, new MutableInt(-1));
-            classesInUse.put(ac, new HashSet<String>());
+            classesInUse.put(ac, new HashSet<>());
         }
         
         if (classLimits.get(ac).value() <= -1)

src/main/java/com/garbagemule/MobArena/MASpawnThread.java

@@ -326,7 +326,7 @@ public class MASpawnThread implements Runnable
     }
 
     private void removeDeadMonsters() {
-        List<Entity> tmp = new ArrayList<Entity>(monsterManager.getMonsters());
+        List<Entity> tmp = new ArrayList<>(monsterManager.getMonsters());
         for (Entity e : tmp) {
             if (e == null) {
                 continue;

src/main/java/com/garbagemule/MobArena/RewardManager.java

@@ -35,14 +35,14 @@ public class RewardManager
     
     public void addReward(Player p, Thing thing) {
         if (!players.containsKey(p)) {
-            players.put(p, new ArrayList<Thing>());
+            players.put(p, new ArrayList<>());
         }
         players.get(p).add(thing);
     }
     
     public List<Thing> getRewards(Player p) {
         List<Thing> rewards = players.get(p);
-        return (rewards == null ? new ArrayList<Thing>(1) : Collections.unmodifiableList(rewards));
+        return (rewards == null ? new ArrayList<>(1) : Collections.unmodifiableList(rewards));
     }
     
     public void grantRewards(Player p) {

src/main/java/com/garbagemule/MobArena/waves/ability/core/ChainLightning.java

@@ -35,7 +35,7 @@ public class ChainLightning implements Ability
         if (target == null || !(target instanceof Player))
             return;
         
-        strikeLightning(arena, (Player) target, new ArrayList<Player>());
+        strikeLightning(arena, (Player) target, new ArrayList<>());
     }
     
     private void strikeLightning(final Arena arena, final Player p, final List<Player> done) {

src/main/java/com/garbagemule/MobArena/waves/ability/core/ShufflePositions.java

@@ -21,7 +21,7 @@ public class ShufflePositions implements Ability
     @Override
     public void execute(Arena arena, MABoss boss) {
         // Grab the players and add the boss
-        List<LivingEntity> entities = new ArrayList<LivingEntity>(arena.getPlayersInArena());
+        List<LivingEntity> entities = new ArrayList<>(arena.getPlayersInArena());
         entities.add(boss.getEntity());
         
         // Grab the locations