Experimental multi-domain support

git-svn-id: http://scm.sipfoundry.org/rep/sipX/branches/sipXconfig-multi-domain@5518 a612230a-c5fa-0310-af8b-88eea846685b
initial multi-domain support

git-svn-id: http://scm.sipfoundry.org/rep/sipX/branches/sipXconfig-multi-domain@5519 a612230a-c5fa-0310-af8b-88eea846685b