Being able to set default import export to off in misc. options.

It's nice to have early game when you only have trucks but would be nice to have an option to have a default off option if i like to setup everything myself. And now i don't use trucks anywhere for anything other than building, hauling from mines or fueling excavators. I've had instances when a storage i don't want to fill being instantly rushed with 15 trucks to fill it because i forgot to turn it off.