Updated fill level.

Do you want to know how full the trailer you are uploading is? Drivers of forage harvesters will love this mod. The fill level of the target trailer is now displayed in the HUD.

It is only available for forage harvesters. For other harvesters, it is not possible to display the fill level of the trailer, since the main game displays fill units combined by crop type.

In version 2.0.1.0:
- Show a notification when the target fill level is 80% or fully filled
- Add support for dumping on objects (unloading triggers, shovels).