Item Whitelist + config file

I created a config file for RegionFlags in which you can insert item IDs.
You then make a region, add the flag "BANITEM" to it, and if a player is using a banned item ID (from the config) it debuffs them (cursed + weak) and informs them not to use the item.

I've also made a working "random buff" function and an anti-pvp zone function (opposite of the forced pvp zone), but I haven't included them in this pull request. If you want it, I can do so later.