Merged revisions 169867 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

........
  r169867 | file | 2009-01-21 19:20:47 -0400 (Wed, 21 Jan 2009) | 4 lines
  
  Read lock the contexts to maintain the locking order when we are notified that the state of a device has changed.
  (closes issue #13839)
  Reported by: mcallist
........


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@169869 65c4cc65-6c06-0410-ace0-fbb531ad65f3