Xfce 4.6 website update and release notes (tour)

[Jérôme Guelfucci]

Hello,

I've been updating the testing branch of the website and mainly the 
"tour" to highlight the new features of Xfce 4.6. There is still some 
work to be done, but it's almost ready.

The tour is available for review here: http://www-test.xfce.org/about/tour

And the website here: http://www-test.xfce.org/

Feel free to comment if you think something can or should be improved, 
or if I missed an important change.

Thanks again to Jannis for the screenshots,

Regards,

Jérôme