first collective mission needs updating for bigsys

[pchilds]

At the moment the mission passes to 2nd stage just on entering Dune requiring no need to find the thing per se. I've got a few proposals to work into the code but as yet haven't got it behave quite right:
*Require proximity to the probe to trigger 2nd stage (using pilot.inrange fn)
*Mission failure on attacking not just destroying the drone as outlined in the brief
*Non deterministic location of drone over multiple systems
*true flags on pilot.add as no collective systems are around Dune/Rockbed etc.

[bobbens]

Should be fixed in master.