Merged revisions 303771 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.8

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  r303771 | rmudgett | 2011-01-25 11:49:20 -0600 (Tue, 25 Jan 2011) | 54 lines
  
  Merged revisions 303769 via svnmerge from 
  https://origsvn.digium.com/svn/asterisk/branches/1.6.2
  
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    r303769 | rmudgett | 2011-01-25 11:42:42 -0600 (Tue, 25 Jan 2011) | 47 lines
    
    Merged revisions 303765 via svnmerge from 
    https://origsvn.digium.com/svn/asterisk/branches/1.4
    
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      r303765 | rmudgett | 2011-01-25 11:36:50 -0600 (Tue, 25 Jan 2011) | 40 lines
      
      Sending out unnecessary PROCEEDING messages breaks overlap dialing.
      
      Issue #16789 was a good idea.  Unfortunately, it breaks overlap dialing
      through Asterisk.  There is not enough information available at this point
      to know if dialing is complete.  The ast_exists_extension(),
      ast_matchmore_extension(), and ast_canmatch_extension() calls are not
      adequate to detect a dial through extension pattern of "_9!".
      
      Workaround is to use the dialplan Proceeding() application early in
      non-dial through extensions.
      
      * Effectively revert issue #16789.
      
      * Allow outgoing overlap dialing to hear dialtone and other early media.
      A PROGRESS "inband-information is now available" message is now sent after
      the SETUP_ACKNOWLEDGE message for non-digital calls.  An
      AST_CONTROL_PROGRESS is now generated for incoming SETUP_ACKNOWLEDGE
      messages for non-digital calls.
      
      * Handling of the AST_CONTROL_CONGESTION in chan_dahdi/sig_pri was
      inconsistent with the cause codes.
      
      * Added better protection from sending out of sequence messages by
      combining several flags into a single enum value representing call
      progress level.
      
      * Added diagnostic messages for deferred overlap digits handling corner
      cases.
      
      (closes issue #17085)
      Reported by: shawkris
      
      (closes issue #18509)
      Reported by: wimpy
      Patches:
            issue18509_early_media_v1.8_v3.patch uploaded by rmudgett (license 664)
            Expanded upon issue18509_early_media_v1.8_v3.patch to include analog
            and SS7 because of backporting requirements.
      Tested by: wimpy, rmudgett
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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@303772 65c4cc65-6c06-0410-ace0-fbb531ad65f3