- added more testcases for keeps in tables
- assign the right table-row element to grid units that are not on the first row spanned
- slightly re-worked the RowGroupBuilder interface to make it more SAX-like
git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@630814 13f79535-47bb-0310-9956-ffa450edef68