By using this command, you are able to return keys to the beginning of a
zone you are not currently in. If you use the command with the argument
'all', you will return all no-rent keys from zones that are on you.
Example using 'unkey': If you are in Elysium, but have the no-rent keys
from Bloodstone on you, this will return ONLY the Bloodstone keys, but not
the Elysium keys to the beginning of Bloodstone.
Example using 'unkey all': If you are in Elysium and have the no-rent
keys from Bloodstone and Elysium on you, this will return all of those
keys to the beginning of the zone they belong to.