Merged revisions 250480 via svnmerge from

Merged revisions 250480 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.4

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  r250480 | jpeeler | 2010-03-03 13:04:11 -0600 (Wed, 03 Mar 2010) | 15 lines

  Make sure to clear red alarm after polarity reversal.

  From the issue:
  The automatic overnight line tests (or manual ones) used on UK (BT) lines causes
  a red alarm on a dahdi / TDM400P connected channel. This is because the line
  uses voltage tests (battery loss) and polarity reversal. The polarity reversal
  causes chan_dahdi to initiate v23 CallerID processing but during this the event
  DAHDI_EVENT_NOALARM is ignored so that the alarm is never cleared.

  (closes issue #14163)
  Reported by: jedi98
  Patches:
        chan_dahdi-1.4-inalarm.diff uploaded by jedi98 (license 653)
  Tested by: mattbrown, Chainsaw, mikeeccleston
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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@250481 65c4cc65-6c06-0410-ace0-fbb531ad65f3