1.) Moved RegionViewport & Reference creation code from PageViewport to Page(Reference).

1.) Moved RegionViewport & Reference creation code from PageViewport to Page(Reference).
2.) Created new .getColumnWidth() in Span to facilitate its querying in layout code.
3.) Removed unneeded retrieveMarker() method in FLM and never-used addMarker method from
SCLM (validation prevents this from occurring)
4.) Removed duplicate flowBPD and flowIPD variables from PSLM (this information
	is already available in the Area classes)
5.) Removed inaccurate setLayoutDimension() code from PSLM; added the
current code in FLM to SCLM in this regard

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/branches/Temp_KnuthStylePageBreaking@198582 13f79535-47bb-0310-9956-ffa450edef68