Implement Limits "offset" command.

Offset command have:
- set <player> <material|entity> <number> - sets the specific limit offset for material or entity.
- add <player> <material|entity> <number> - adds the specific limit offset for material or entity.
- remove <player> <material|entity> <number> - removes the specific limit offset for material or entity.
- reset <player> <material|entity> - resets limit offset for material or entity.
- view <player> <material|entity> - views the specific limit offset for material or entity.

Relates to the #149

src/main/java/world/bentobox/limits/Limits.java

@@ -12,8 +12,8 @@
 import world.bentobox.bentobox.api.addons.GameModeAddon;
 import world.bentobox.bentobox.api.user.User;
 import world.bentobox.bentobox.database.objects.Island;
-import world.bentobox.limits.commands.AdminCommand;
-import world.bentobox.limits.commands.PlayerCommand;
+import world.bentobox.limits.commands.admin.AdminCommand;
+import world.bentobox.limits.commands.player.PlayerCommand;
 import world.bentobox.limits.listeners.BlockLimitsListener;
 import world.bentobox.limits.listeners.EntityLimitListener;
 import world.bentobox.limits.listeners.JoinListener;

src/main/java/world/bentobox/limits/commands/AdminCommand.java → src/main/java/world/bentobox/limits/commands/admin/AdminCommand.java

@@ -1,4 +1,4 @@
-package world.bentobox.limits.commands;
+package world.bentobox.limits.commands.admin;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -10,6 +10,8 @@
 import world.bentobox.bentobox.api.user.User;
 import world.bentobox.bentobox.util.Util;
 import world.bentobox.limits.Limits;
+import world.bentobox.limits.commands.player.LimitPanel;
+
 
 /**
  * Admin command for limits
@@ -27,7 +29,9 @@ public class AdminCommand extends CompositeCommand {
     public AdminCommand(Limits addon, CompositeCommand parent) {
         super(parent, "limits");
         this.addon = addon;
-        new CalcCommand(addon, this); 
+
+        new CalcCommand(this.addon, this);
+        new OffsetCommand(this.addon, this);
     }
 
     /* (non-Javadoc)

src/main/java/world/bentobox/limits/commands/CalcCommand.java → src/main/java/world/bentobox/limits/commands/admin/CalcCommand.java

@@ -1,4 +1,4 @@
-package world.bentobox.limits.commands;
+package world.bentobox.limits.commands.admin;
 
 import java.util.ArrayList;
 import java.util.List;