mappings/Makefile: Only clean up a core map (intermediate format->VegBIEN) when it's modified. Note that the .last_cleanup files need to be under version control to prevent cleanups upon running any map command in a new checkout.
mappings/Makefile: Only clean up a core map (intermediate format->VegBIEN) when it's modified. Note that the .last_cleanup files need to be under version control to prevent cleanups upon running any map command in a new checkout.