Added update checker and a blacklist remove command
- Added update checker and prints to the console if the plugin is out of date
- Added /recyclingbin blacklist add|remove [material] instead of only being able to add items
- Updated lang.yml file for additional messages relating to removing from the blacklist
- Fixed tab completer for materials when adding to the blacklist
- Fixes a small bug where adding a blacklisted item would send a confirmation message twice