Tow Bar v1.2.1.0

A tow bar gets attached to the back of a vehicle and can be used for pulling another vehicle.

Changelog: 1.2.1.0
- fixed for vehicle type "selfPropelledSprayer"
- fixed for vehicle type "combineDrivable"
- fixed for vehicle type "combineCutterFruitPreparer"
- fixed for vehicle type "cottonHarvester"
- fixed for vehicle type "drivableMixerWagon"
- fixed for vehicle type "loaderVehicle"
- fixed for vehicle type "selfPropelledMower"
- fixed for vehicle type "forwarder"
- fixed for vehicle type "woodHarvester"

Changelog: 1.2.0.0
- fixed for vehicle type "woodCrusherTrailerDrivable"

Changelog: 1.1.0.0
- added value for brakeForce
- fixed with overwritten function, the nil value for function Attachable.getCanAIImplementContinueWork
- fixed with overwritten function for Attachable.getIsImplementChainLowered
- clean incorrect game values