- add a UserEvent action that allows a manager client to "broadcast" an event

  to all connected manager clients
- update the UserEvent application to use the application argument parsing
  macros and to allow headers to be specified as pipe delimeted arguments
  (issue #5324, original patch by outtolunc, committed patch by Corydon)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@29017 65c4cc65-6c06-0410-ace0-fbb531ad65f3