Attach the selected variant to KnuthPageNode in order to propagate the information down to area tree creation.
Patch by Seifeddine Dridi, applied with some modifications.


git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/branches/Temp_WhitespaceManagement@1550847 13f79535-47bb-0310-9956-ffa450edef68