Added '!whitelist clear' command for limited whitelisters:
This allows limited whitelisters to remove all their whitelisted minecraft names and regain the ability to whitelist up to the current max whitelist amount
The user will also have their Discord whitelisted-roles revoked if whitelisted-role-auto-remove is enabled (the role(s) will be re-added upon a successful whitelist)
This feature can be disabled by setting allow-limited-whitelisters-to-unwhitelist-self to false
Changed logging solution to Logback
re-shaded dependencies to avoid conflicts with other plugins