LP#1136084: drop silent dependency on 'bsdmainutils' Debian/Ubuntu package

colrm is a perfectly good command, but isn't guaranteed to be
present on a minimal Ubuntu system.  This patch replaces ti with
with cut, which is more likely to be present (including on *BSD
servers).

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Signed-off-by: Jason Stephenson <jstephenson@mvlc.org>