Implemented limited support for extension properties through new methods on ElementMapping (backwards-compatible).
Moved block-progression-unit into the fox: namespace.
Implemented new extension properties: fox:orphan-content-limit and fox:widow-content-limit for fo:table and fo:list-block. See documentation for details.
Bugfix in ElementListUtils.removeLegalBreaks (concerning box/glue combinations). Added a unit test to cover the problem.
git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@442282 13f79535-47bb-0310-9956-ffa450edef68