Runtime : Ensure that a random PSK secret compatible with stunnel is generated if -s commandline switch is used. Stunnel service is restarted after generation, using spawn_subprocess. TODO : give stunnel restart command as a commandline parameter.

          <xsd:attribute name="Command" type="xsd:string" use="optional" default="make -C %(buildpath)s all BEREMIZSRC=%(src)s BEREMIZCFLAGS=%(cflags)s MD5=%(md5)s USE_BEREMIZ=1 FROM_BEREMIZ=1"/>