Spam message when writing a sign with "Barrel" text on it without valid barrel

[Thorinwasher]

When the user lacks the permissions brewery.createbarrel.small and brewery.createbarrel.big, a message will be sent to the player when they write a sign with the text "Barrel" on it.

There's also a setting requireKeywordOnSigns, which when false would remove the barrel text criteria. Which means that whenever a user without said perms writes any sign, they will get the message.