Added support for stopping MineralVein from interacting with player placed blocks.
Added support for locking blocks so players cannot remove them with silk touch.
Added persistence for both player placed block tracking and locked block tracking.
Added permissions that allow you to specify if a group is allowed to interact with MineralVein (e.g. when they mine blocks they have chance to respawn) as well as a separate permission that allows users to lock and unlock blocks.
