Xfce 4.6 website update and release notes (tour)

[Jérôme Guelfucci]

Hello,

The website should be ready now.

I updated the projects page to add the new xfconf projects, fixed a lot 
of broken links (websvn -> viewvc migration), updated the developpers 
list...

The credits should now be up to date. And I updated the tour to add the 
missing item quoted by Olivier.

Please tell me if you find things that should still be updated, typos or 
missing things...

Jérôme