Mixer wagon with 64.000l capacity

All kudos to Modder Rolf for the LS17 version, and alfalfa6945 for the easyAutoload script.

I just did the conversation to FS19, and added some minor things.

* You can configure an additional terminal which makes it easier to see the current filllevel. This can be turned around to both sides.
* Choice of filllevel marker. Standard bar or a cute little cow ;)
* Different wheels are configurable