Adapted sip_subscribe_rls script to the notification system

darcs-hash:20090211192045-1e3d8-19fb22602e19bacf4a2b2bbe7f7663fbb7ee9536
Adapted sip_subscribe_rls to the new XML API

darcs-hash:20090211192849-1e3d8-348095960c7c14069aef01727cc3300424a2dcd5