Refactored delivery missions to use pre-spawned commoners

Scripters should change any commoners being spawned to use
core.staticService.spawnCommoner instead of spawnObject (see
mos_eisley.py in static_spawns\tatooine for an example). The
spawnCommoner method will add required attachments and set the proper
options bitmask in order for the missions to function properly.

Note that delivery missions won't work unless you have spawned buildouts
on the planet you are requesting the missions on due to this change.