Logistic Artillery

adds:
- artillery requester combinators (that call artillery strikes)
- cargo shells (that deliver a stack of items)
- strong chests (to catch cargo shells)
- manual artillery turrets (that don't auto-fire at enemies)

there's a red+green tech that unlocks everything. (but, you don't get the explosive shells or the targeting remote that early)

Artillery Requester Combinator

the combinator calls in artillery when it receives the artillery remote signal on the circuit network. it will offset the target position using X and Y signals. And you can select the ammo type and a constant Y offset on the combinator's GUI.