Course generator headland

Headland settings will only show up, when you have set at least 1 at Number of headlands.
You gain options for where to start on, corner settings, direction and overlap.
Headlands are highly suggested to prevent tools leaving the field when turning.

• Start work on: As mentioned in the extended AI Menu, the field position is used to set the start or end position for the field work course.
  When set to start on headland, it tells where the start should be. When changed to start on rows, it will tell where to end the work.
• Headland corners: Smooth will have a simple smoothing over the corners, This works for all tools, but will lead to tiny unworked patches in the corners.
  They can be reduced with overlap, but never disappear. Sharp will generate a turn based on the angle of the field border angle.
  Round will take the current selected vehicles turn radius into account to have the best round corner for that tool.
• Headland direction: clockwise or counter-clockwise. This can be important for combines and harvesters, depending on wich side the pipe or conveyor belt is.
• Headland overlap: How much % overlap all headlands should have. The first one will have no overlap with the field border, but the inner ones will overlap with their neighbour.