YafaRay plugin; update roadmap and change list

[micheus]

I just updated my git brach of yafaray for build it here - all fine. Also, I installed the SSS version referenced and was good to know about the "-pp" command line option - no more register to edit. Thanks!

But, I would like to make two suggestions ref. to Plugin Options dialog:
- as the plugins folder is always under the path of yafaray-xml.exe file, why not build the path automatically when building the command line?
- I believe that the "-db" option would be in better place if it was in the Render Options dialog.

I noticed that it always generate a .png file as output, as POV-Ray used to do too. I noticed at the documentation that it would export to .BMP, .PNG and .EXR (maybe .tga?).
So, as I just implemented the option for choose the output file format, I can do that to yafaray too - if you want.

/Micheus