AreaHelper
Adds new actions to AreaManager (inclusion/exclusion) and combinations of these actions
Actions on areas in AreaManager:
shift+click = include(remove inclusion if was included)
alt+click = exclude(remove exclusion if was excluded)
shift/alt+mouseover = show combined area for selected Thing
This mod modifies your save, but you can turn it on/off without errors (in theory) when reloading/saving, because all information about the mod is stored in a separate node of the save file.
In case of errors, you can delete the "areaHelper" node in the save file.
I am open to suggestions for improvements and fixes
