Added IPv6 support to rtp channel.

git-svn-id: http://yate.null.ro/svn/yate/trunk@5670 acf43c95-373e-0410-b603-e72c3f656dc1
Set scope id when changing rtp addresses to avoid comparison mismatch.

git-svn-id: http://yate.null.ro/svn/yate/trunk@5671 acf43c95-373e-0410-b603-e72c3f656dc1
Handle and set IPv6 addresses in SDP.

git-svn-id: http://yate.null.ro/svn/yate/trunk@5672 acf43c95-373e-0410-b603-e72c3f656dc1
Added SIP IPv6 support.

git-svn-id: http://yate.null.ro/svn/yate/trunk@5673 acf43c95-373e-0410-b603-e72c3f656dc1