Graphics2d builder and testdriver

[rototor]

I've started to update the Graphics2D support. To do so I've created a Java2DRendererBuilder and called it in the testdriver to write a PNG output beside the PDF output. I also tried to reproduce #63 with this, but I could not.

The PNG currently shows some missing features and bugs:

• CMYK colors are not supported at the moment. We should just use some simple hardcoded CMYK->RGB conversion for that as a start. I think using some kind of ICC-based color conversion is overkill here.
• For whatever reason the text in the svg-sample is rendered broken. I think for Java2D the correct fix is to just use TextLayout and let TextLayout do all the rendering. Then Java2D will have as much Bidi support as Java itself has.
• Also the (partly) unused support for drawing selections is obsolete. If someone wants to display HTML in his application he will likely rather use the JavaFX-WebKit component from the JDK. For me the Java2D support is mostly the ability to render HTML to an image, so selections aren't really needed. I think the selection support should just be deleted.
• The current place where I've put the Java2DRendererBuilder is not the best one. Also the innerclasses should maybe be outerclasses in some other packages. Feel free to suggest a better place.

When I find time again I would like to work on this things. Do you have any objections?

[danfickle]

Hi @rototor

Thank you again, this looks really good. I'm going to merge now and then I'll try to put the Java2D output related code in its own sub-module. We can then continue the discussion at #73

Regards,
Daniel.