Usermap based on client domain.

[Jason Coleman]

	I've been experimenting with the usermap function, and the only
problem I've been running into is that multiple domains will be connecting
to our samba server. I've been trying to figure out a way to base the
usermap on the domain which is attempting to connect, but all I cac come
up with is to use IP adresses or Netbios names. Any other ideas?
						--Jason Coleman