[schema2sql] properly consider skip_relations parameters. This is the same bug as yams #286912. Also, introducing a unique function telling if the relation should have a table or not unhide some other problems related to computed relation, or missing skipped relations information.

#!/bin/sh -e
if [ "$1" = "purge" ] ; then
        update-rc.d cubicweb remove >/dev/null
fi
 
#DEBHELPER#
 
exit 0