Make the event cancellable.
Potential use case: You have a plugin that allows players to buy an ad by placing a sign:
"[Buy Ad]
127.0.0.1
$50"
The sign would never actually become that because AntiAdvertiser cancels it. The plugin can listen to the PlayerAdvertiseEvent and cancel it if the detected ad is on a sign and begins with "[Buy Ad]"
Writing messages to file is now handled by a listener to the PlayerAdvertiseEvent (let's use our own API, yay!)
Signs now have one line per line (line break instead of |), the | is added when writing to file
Tell the console somebody tried advertising & add logger
Add Metrics