Add COLP support to chan_dahdi/sig_pri.

Add Connected Line Presentation (COLP) support to chan_dahdi/libpri as an
addition to issue 8824.  This is the chan_dahdi/sig_pri portion.  COLP
support is now available for any switch for which libpri supports COLP
(currently ETSI PTP, ETSI PTMP, and Q.SIG) with this patch.

(closes issue #14068)
Tested by: rmudgett

Review: https://reviewboard.asterisk.org/r/340/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@213007 65c4cc65-6c06-0410-ace0-fbb531ad65f3