This introduces a new dialplan function, DEVSTATE, which allows you to do some

pretty cool things.

First, you can get the device state of anything in the dialplan:
  NoOp(SIP/mypeer has state ${DEVSTATE(SIP/mypeer)})
  NoOp(The conference room 1234 has state ${DEVSTATE(MeetMe:1234)})

Most importantly, this allows you to create custom device states so you can
control phone lamps directly from the dialplan.
  Set(DEVSTATE(Custom:mycustomlamp)=BUSY)
  ...
  exten => mycustomlamp,hint,Custom:mycustomlamp


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@54261 65c4cc65-6c06-0410-ace0-fbb531ad65f3