[undo, transactions] Adds a property in the transaction API. (closes #2202953)
Required by forthcoming changes in undo_web.diff
#! /bin/sh -e#if [ "$1" = configure ]; then if which install-docs >/dev/null 2>&1; then install-docs -i /usr/share/doc-base/cubicweb-doc fifi#DEBHELPER#exit 0