Add timestamp to response to "Ping" manager action.

(closes issue #14596)
Reported by: JimDickenson
Patches:
      pong2.diff uploaded by JimDickenson (license 710)



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@203783 65c4cc65-6c06-0410-ace0-fbb531ad65f3