Add IPv6 Support To Manager

This patch adds IPv6 support to AMI.

(Closes issue ASTERISK-19965)
Reported by: Michael L. Young
Tested by: Michael L. Young
Patches:
    ami_ipv6_v3.diff uploaded by Michael L. Young (license 5026)

Review: https://reviewboard.asterisk.org/r/1968/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@369126 65c4cc65-6c06-0410-ace0-fbb531ad65f3