New feature added: Lockdown!

The main command is:

/lockdown [reason]

(not /sentry lockdown) - It allows you to lock the server temporarily, kick all the online players and only allow specific players with the 'sentry.bypass.lockdown' permission to join the server.

Fixes

• Fixed legacy versions issue with the "sentry.command" permission.
• Removed sentry.command as a permission requirement.

Changes

• Enhanced "notifications off" reminder to be more direct and just better in general.
• Enhanced the warning and notifications message format.