triggered when you get a new structure
eventStructureBuilt(structure[, droid])
An event that is run every time a structure is produced. The droid parameter is set if the structure was built by a droid. It is not triggered for building theft (check eventObjectTransfer for that).
structure = Structure object
droid = Droid object (only if the building was built by a droid)
if a DROID_CONSTRUCT was building it, then this event gets triggered after the transition from BEING_BUILT to BUILT.
the event also gets called if you use addStructure() (I think?)