Whitelisted Events to prevent nuitools exploits

[NikolaiFN]

Added whitelist check on events so people cant trigger random events outside of those allowed with NUItools

[LiamDormon]

I think it's better practice to just secure your events, this won't stop a hacker with an executor from exploiting it. Add server side callbacks to all of your events and only allow it if the source is allowed to.