Some refactoring in the XML handling area which results in more code reuse and less...

Some refactoring in the XML handling area which results in more code reuse and less redundancy.
Support for i-f-o for the AFPRenderer including a Graphics2DAdapter so extensions like Barcode4J can paint barcodes more efficiently (i.e. not via SVG).
The SVGConverter class could now be removed except for the writeImage() method because the same functionality is now covered by the Graphics2DAdapter via renderDocument() in the renderer.
PCL and AFP now use practically the same extension painting code (both render to bitmap images).

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@399306 13f79535-47bb-0310-9956-ffa450edef68