Re-organized configuration to use a ChestKitsKit object instead of a
list of items. This is in preparation for adding (functional) cooldowns.
Added "cooldown" command that allows users to set the cooldown of a kit.
The cooldown still doesn't have any effect, but it does exist.
Fixed slight error.
Added cooldown manager to keep track of cooldowns.
Hooked the new cooldown manager into the /ckit KITNAME command.
Added default value for permission ckit.cooldown
Fixed the cooldown command's 'success' message. Changed "seconds
remaining" message to be an over-estimation instead of under-estimation
of how many seconds remain.
Added better time formatting.
Fixed a bug that caused the last access time to update incorrectly.