Allow Setting / Reading the pickupgroup of a channel with func_channel.c
  
  (closes issue #19045)
  Reported by: irroot
  
  Review: https://reviewboard.asterisk.org/r/1148/



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@320772 65c4cc65-6c06-0410-ace0-fbb531ad65f3