Added check that failes, when jars are not signed.

        <pathelement path="${warfile}"/>

      </path>

    </signjar>

    <fail message="Signing failed." >

      <condition>

        <not>

          <and>

            <issigned file="${onionoo.jarfile}"/>

            <issigned file="${warfile}"/>

          </and>

        </not>

      </condition>

    </fail>

  </target>

  <target name="tar" depends="signjar">