TS3 Audio/TTS Notification on Join/Left 2.1

Changelog:

~ Fix: messages of engine.saveConfig() for the sinusbot version: 1.0.0-beta.2

Changelog:

* jumped to the 2.0, because this update makes the script supporting the new 1.0.0 beta.
~ Update to new 1.0.0 engine - tested on Sinusbot 1.0.0-beta.1-06a54d7 (Ubuntu Server 18.04.2 LTS).
~ Fix: Blacklist & Whitlist clientUID's is now working. (Reported by @tega and @CPB)
~ Fix: [internal] better, more consistent code

Changelog:

~ Add: TTS advertisement script: Now you can set TTS / Audio at regular intervals. (Request @SgtWhiskyFuzz: https://forum.sinusbot.com/threads/audio-notification-on-join-left.5284/#post-30466)
~ Add: TTS Server Group join message: Now you can set a user filter. (Request @SgtWhiskyFuzz: https://forum.sinusbot.com/threads/audio-notification-on-join-left.5284/#post-30466)
~ Add: Now you can convert more commands (like %n --> nickname) in the multilines to text. You can find all commands in the Forum Thread.
~ Update: better, more configurable configuration
~ Fix: [internal] better, more consistent code
~ Fix: [internal] add .sinusbotConvert - function
~ Fix: [internal] add .plural - function

Changelog:

~ Add: Possibility to select a audio file. (Request @Killer0561: https://forum.sinusbot.com/threads/request-welcome-join-sound-script.4608)
~ Add: You can only set up audio files and no TTS messages by writing a "none" or "undefined" in multiline.
~ Add: Possibility to select that audio is playing/saying when a client join/leave the channel in which the sinusbot is. (Request @m8rm: https://forum.sinusbot.com/threads/audio-notification-on-join-left.5284/#post-30438)
~ Add: Check for Discord-Backend
~ Fix: missing "locale" setting (Request @m8rm: https://forum.sinusbot.com/threads/audio-notification-on-join-left.5284/#post-30438)
~ Fix: [internal] add .startsWith - function
~ Fix: [internal] Better, more consistent code