Fixed issue with default config and messages values when updating plugin or when deleted by accident.
Fixed issue when renaming a mine duplicated it.
Changing a mine location now applies instantly.
Added and changed the system of placeholders.

New featuers:
- Update checker
- AutoPickup
- bStats
Commands:
- showxp
Placeholders:
- %blocks_mined%
- %blocks_mined_formatted%
- %xp_formatted%