1. To facilitate comprehension of the Renderer classes, added the remaining three...

1.  To facilitate comprehension of the Renderer classes, added the remaining three methods in the Renderer interface to AbstractRenderer: startRenderer(), stopRenderer(), and setupFontInfo().  SetupFontInfo() remains abstract, the other two have blank definitions.
2.  Removed the blank definitions of startRenderer() and stopRenderer() from PrintRenderer, these are now defined in AbstractRenderer.
3.  Member string variables "producer" and "creator" were added to AbstractRenderer and are now populated by its setProducer() and setCreator() methods; removed these functions from the several subclasses that were handling these strings equivalently.

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@196776 13f79535-47bb-0310-9956-ffa450edef68