Added site_node::conn_url which provides output like ns_conn url, but adjusts depending on if connection is via main domain or a site host_node.
Also added parameter UseHostnameDomainforReg to acs-tcl for easier management of host_node mapped domains that share the main domain's HTTPS connection for secure sessions and login. Revised ad_get_login_url accordingly. Default behavior is unchanged.
Still need a way to transfer session state between host_nodes (since the user account is shared between them). Any suggestions?