Swaps highlighted trains between automatic/manual. If no train is highlighted, provides a selection tool to drag across multiple trains to bulk swap modes
I've uploaded 1.0.5 which has a new per-play mod setting "No Toggling". We can't detect a left-click or right-click, but selection tools have an alt-mode triggered by holding shift whilst dragging we can use.
When the mod settings enabled, dragging the selection tool over trains will now only set them to automatic, and alt-mode will set them all to manual (i.e. holding shift whilst dragging)
