Merged revisions 206938 via svnmerge from

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

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  r206938 | dvossel | 2009-07-17 11:05:06 -0500 (Fri, 17 Jul 2009) | 14 lines
  
  SIP incorrect From: header information when callpres is prohib
  
  Some ITSP make use of the "Anonymous" display name to detect a
  requirement to withhold caller id across the PSTN. This does
  not work if the display name is "Unknown".
  
  (closes issue #14465)
  Reported by: Nick_Lewis
  Patches:
        chan_sip.c-callerpres.patch uploaded by Nick (license 657)
        chan_sip.c-callerpres_trunk.patch uploaded by dvossel (license 671)
  Tested by: Nick_Lewis, dvossel
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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@206939 65c4cc65-6c06-0410-ace0-fbb531ad65f3