Add option to delete essentials homes when players are kicked from Factions. Adds #1089.

This option is set to true by default in the config.yml for new users, users that are updating need to add delete-ess-homes: true to their config.yml to get this new option enabled.

src/main/java/com/massivecraft/factions/integration/Essentials.java

@@ -14,11 +14,14 @@ public class Essentials {
 
     private static IEssentials essentials;
 
-    public static void setup() {
+    public static IEssentials setup() {
         Plugin ess = Bukkit.getPluginManager().getPlugin("Essentials");
         if (ess != null) {
             essentials = (IEssentials) ess;
+            return essentials;
         }
+
+        return null;
     }
 
     // return false if feature is disabled or Essentials isn't available