Use addUnsafeEnchantment instead of addEnchantment

Since the enchantment was already present on the item, there's no need to check if it's valid. This also avoids any errors that may occur when trying to repair an item with non-standard enchants.

Fixes #1561
New and Improved Scoreboard System

 - Scoreboards now AUTO-UPDATE
 - Scoreboards now COME IN COLOR
 - If you want, they can come in EVERY COLOR (Config setting)
 - Scoreboards can be displayed alongside chat output!
 - Prevention of denial of service to SQL via spamming /mctop using a cooldown
 - Added /mccooldown command to show cooldowns for all available skills
Create a utility method in SkillUtils to easily check ability cooldowns