rearranged entire SV_Physics process (which may break mods but I hope not!):

rearranged entire SV_Physics process (which may break mods but I hope not!):
each operation (move, prethink, think, postthink) is now a separate stage (as an optimization mainly)
moves are now done before prethinks, thinks, and postthinks so that think-spawned entities do not move on their first frame (this fixes the issue that all projectiles appeared some distance from the player, dependent on server framerate, so rocket trails and other things look correct)
added a relink of any entity that moves for any reason (just an origin compare), not sure if this is a good idea but it is more consistent

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@4917 d7cf8633-e32d-0410-b094-e92efae38249