Added option to try to provide ringback from analog card or gateway if early media is not available from the called party. git-svn-id: http://voip.null.ro/svn/yate@4189 acf43c95-373e-0410-b603-e72c3f656dc1
git-svn-id: http://voip.null.ro/svn/yate@4032 acf43c95-373e-0410-b603-e72c3f656dc1
git-svn-id: http://voip.null.ro/svn/yate@1549 acf43c95-373e-0410-b603-e72c3f656dc1