[source schema] fix permission pb on cw_host_config_of relation + add composite on cw_source, so entities from a source are properly removed when the source is removed

#! /bin/sh -e
 
case "$1" in
    purge)
	rm -rf /etc/cubicweb.d/
	rm -rf /var/log/cubicweb/
	rm -rf /var/lib/cubicweb/
    ;;
esac
 
#DEBHELPER#
 
exit 0