Map zp_nation for ZP

zp_nation (release 7) By hi New changes -Added clip brush over the fence (that was an accident that it wasn't there) -crappy new secret room area! -some lights made illusionary to prevent people jumping into them and falling into the acid -Added plenty of player_starts to prevent people getting stuck inside other players Have fun! zp_nation (release 6) New changes -re-added cow room -guns have been moved a bit -the elevator has been changed into an elevator shaft with the elevator at the bottom, to lessen camping -music for disco room, hit the controls a few times, it will turn on -vents have been changed, hopefully to lessen camping -put a fence outside