Bug Fixes, new -hn flag

FIxed Segfaulting when running ./daemonmap with 0 args, and when trying to generate navMeshes from *.bsp's that don't have brush geometry in a certain order(I'm fairly certain it will catch this but seeing as I can't reproduce I don't know for sure). Also added new help flag "-hn" which is a  3 liner that prints navmesh steps.