[server] extract "no pooler" CnxSet class to a _BaseCnxSet class So we get rid of "if self._queue is None" in each method of _CnxSetPool Also add helper get_cnxset(source, size) to instantiate the correct pooler class.

#!/bin/sh -e

if [ "$1" = "purge" ] ; then
        rm -rf /etc/cubicweb.d/
        rm -rf /var/log/cubicweb/
        rm -rf /var/lib/cubicweb/
fi

#DEBHELPER#
 
exit 0