Drop some more stuff in modelSwarm drop

(By the way, 'deleteAll' causes all the deleted objects to execute their
drop method)
Got habitat spaces to drop.
Drop a few more things but problem not solved.

I searched TroutModelSwarm and tried to drop every object created, and
made sure fish and cells and habitatspaces are all dropped. But we still
don't free a bunch of memory at the end of each run.