Rework

Hi, I saw you plugin and I think it would be a shame to let it die. So here's the update :smile: 

+ I updated the plugin to last version.
+ I removed nms stuff which was not working and not supported by bukkit.
+ I moved the xp storing from durability (which doesn't work anymore) to the lore
+ I refactored the event handlings so they are more logical / readable
+ I fixed the sign not updating when bank was removed
+ I made bottles right clickable in the air

I found a bug which is not fixed right now : When breaking a bank, if the block is replaced and interacted with, the xp which was stored inside before is still in.

Also, while fixing the indentation, my editor changed tabs to spaces. I can take the time to make them tabs again if you really want :wink: 

Also, if you don't want to maintain the plugin anymore, I'd be glad to maintain it anyway.