Changes chan_local channels to use an 8 digit hex identifier generated
atomically and sequentially in order to eliminate the chance of having
multiple channels with the same name during high call volume situations.
(issue ASTERISK-20318)
Reported by: Dan Cropp
Review: https://reviewboard.asterisk.org/r/2104/
git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@372902 65c4cc65-6c06-0410-ace0-fbb531ad65f3