Remove unused fields, imports, warning suppressions.

Just a bit of spring cleaning!

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

@@ -859,7 +859,6 @@ public class ArenaImpl implements Arena
     }
 
     @Override
-    @SuppressWarnings("deprecation")
     public void revivePlayer(Player p) {
         removePermissionAttachments(p);
         removePotionEffects(p);

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

@@ -264,10 +264,6 @@ public class MobArena extends JavaPlugin
         return lastFailureCause;
     }
 
-    public File getPluginFile() {
-        return getFile();
-    }
-
     @Override
     public FileConfiguration getConfig() {
         if (config == null) {

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

@@ -5,7 +5,6 @@ import com.garbagemule.MobArena.things.Thing;
 import org.bukkit.entity.Player;
 
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -14,16 +13,10 @@ import java.util.Set;
 
 public class RewardManager
 {
-    @SuppressWarnings("unused")
-    private MobArena plugin;
-    @SuppressWarnings("unused")
-    private Arena arena;
     private Map<Player,List<Thing>> players;
     private Set<Player> rewarded;
     
     public RewardManager(Arena arena) {
-        this.plugin   = arena.getPlugin();
-        this.arena    = arena;
         this.players  = new HashMap<>();
         this.rewarded = new HashSet<>();
     }
@@ -39,12 +32,7 @@ public class RewardManager
         }
         players.get(p).add(thing);
     }
-    
-    public List<Thing> getRewards(Player p) {
-        List<Thing> rewards = players.get(p);
-        return (rewards == null ? new ArrayList<>(1) : Collections.unmodifiableList(rewards));
-    }
-    
+
     public void grantRewards(Player p) {
         if (rewarded.contains(p)) return;
         

src/main/java/com/garbagemule/MobArena/util/config/ConfigUtils.java

@@ -1,6 +1,5 @@
 package com.garbagemule.MobArena.util.config;
 
-import com.garbagemule.MobArena.ConfigError;
 import org.bukkit.Bukkit;
 import org.bukkit.Location;
 import org.bukkit.World;