Believe to have fixed MetalClips..

MetalClips will no longer use setHealth().
MetalClips takes into account the 60% damage reduction a full set of
Iron Armor gives, and thus gives a 120% bonus to the damage to counter
it.
Corrected the damage MetalClips does.

Instead of multiplying by 240% I added 120% to the base damage.
Removed Creative Gamemode check in MetalClips

It was un-needed and frankly just wasted space. I'm not using
setHealth() anymore so its purpose is void.
Merge pull request #64 from Carbogen/master

Fixed damage from MetalClips.