Added MetalClips ability...

- Added "EnderLance" to the /pk who command.
- New Ability: MetalClips:

MetalClips is an ability for Metalbenders with Iron Ingots in their inventory. To use, a metalbender must click towards an entity of any kind. If the entity is a Zombie, a Skeleton, or a Player, the iron ingot thrown will wrap itself around the target as armor. This can be repeated up to 4 times, each time increasing the effectiveness of the ability:

With one MetalClip attached to their target, a metalbender may attract their enemy towards them like a magnet.
With two MetalClips attached to their target, a metalbender may slowly attract their enemy towards whatever they are looking at, including the sky!
With three MetalClips, the speed is increased. The metalbender now has full control over the movements of the enemy.
With four MetalClips, the enemy gets crushed by the pressure exerted on the clips. This causes configurable damage to the enemy and may well kill them (if it does, pieces of armor may drop, this is to be fixed).

The metalbender may control the entity for up to 10 seconds (default, option in the config)
If the metalbender misses the entity, the clip will fall to the ground.
If the hit entity is not a Zombie, a Skeleton, or a Player, the entity will take damage and the ingot will drop.
When the usage time ends, the entity will drop and the iron will too, so it can be recollected.

Additionally, if the metalbender is feeling lazy, they can sneak while not targeting an entity to attract all nearby iron ingots towards themselves (radius configurable).

MetalClips can be used to help fellow players across chasms (of minimal width), move them out of danger, or hurt them badly.

~Carbogen.

Thanks to Fly for the idea.