New Feature: Xp bank, Xp tradeing, and Xp leaderboards

Adding this since some people had some issues from deaths while gaining xp so this should add some fun competition to the server and fix some errors.

Also monster spawners should no longer work that way it is a fair competition and not one guy standing at a spawner all day.

Commands:

/xbank deposit [amt]
With this command it simply deposit the amount of levels you specify, if you have the amount on your character.

It displays your current levels after typed.

/xbank withdraw [amt]
Allows the player to withdraw the specified amount of experience from their xbank.

/xbank send [player name] [amt]
Allows the player to send experience to any online player on the server.

/xbank balance
Simply tells the player their current balance and XP level.

/xbank top
Get top 10 players!