defaultcolor on Pagetype should not prevent grid to show

[pgundlach]

<?xml version="1.0" encoding="UTF-8"?>
<Layout xmlns="urn:speedata.de:2009/publisher/en"
  xmlns:sd="urn:speedata:2009/publisher/functions/en"
  xmlns:xi="http://www.w3.org/2001/XInclude"
  version="3.1.20">
  <Trace grid="yes" gridallocation="yes"/>

  <Pagetype name="x" test="true()" defaultcolor="black">
    <Margin left="10mm" right="10mm" top="1cm" bottom="14mm"/>
  </Pagetype>

  <Record element="data">
    <PlaceObject>
      <Textblock>
        <Paragraph><Value>xxxxx</Value></Paragraph>
      </Textblock>
    </PlaceObject>
  </Record>

</Layout>

[pgundlach]

This fix is related to #143 (slow typesetting)