Set filter on spidertron ammo slots for automated reloading

[rjlan@rjlan.net]

Would like spidertron to either remember what was in its ammo slot after exhausting supply or ideally set a filter on the slots so that you get the same item in the slot when automating reloading via the logistics network.

I like to have 3 of the slots use regular rockets for taking out nests/worms and one slot use explosive for mobs but if you expend all your ammo then your slots get randomly filled by whatever the logistics network happens to throw in there. If I end up with more then one slot with explosive rockets I will expend more explosive rockets long before I run out of regular rockets or end up not use any explosive rockets at all if those don't get slotted. And since I have requests set to a specific ratio and production set to match those requests I can end up with a production imbalance.