Merged revisions 337720 via svnmerge from

Merged revisions 337720 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.8

........
  r337720 | rmudgett | 2011-09-22 16:29:46 -0500 (Thu, 22 Sep 2011) | 18 lines

  Made ISDN not add numbering plan prefix strings to empty numbers.

  When the Caller-ID is restricted, the expected behavior is for the
  Caller-ID to be blank.  In chan_dahdi, the national prefix is placed onto
  the Caller-ID number even if it is restricted (empty) causing the
  Caller-ID to be the national prefix rather than blank.

  This behavior was lost when sig_pri was extracted from chan_dahdi.

  * Made not add prefix strings to empty connected line, calling, and ANI
  number strings.

  (closes issue ASTERISK-18577)
  Reported by: Kris Shaw
  Patches:
        jira_asterisk_18577_v1.8.patch (license #5621) patch uploaded by rmudgett
  Tested by: Kris Shaw
........

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/10@337721 65c4cc65-6c06-0410-ace0-fbb531ad65f3