[Feature] Clan Tax Event

Issue #12 resolved
Rasgnarok created an issue

Following ticket https://bitbucket.org/Kippers/mcclans-core-sponge/issues/11/feature-clan-taxing-and-member-fee ; To allow GriefPrevention (and any other plugin) to add their own tax in sync with this one, an API event is required when McClans executes the clan tax. Then, all possible clan taxes would be executed together whenever the interval for taxing (defined in the admin config, see previous ticket) is complete.