Merged revisions 298773 via svnmerge from

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

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  r298773 | marquis | 2010-12-17 12:26:31 -0500 (Fri, 17 Dec 2010) | 10 lines
  
  Fix parsing of mwi => lines in sip.conf
  
  Reworking parsing of mwi => lines to resolve a segfault.  Also add a set of unit tests for the function that does the parsing.
  
  (closes issue #18350)
  Reported by: gbour
  Tested by: Marquis, gbour
  
  Review: https://reviewboard.asterisk.org/r/1053/
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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@298774 65c4cc65-6c06-0410-ace0-fbb531ad65f3