Don't display the projects on the welcome page, and update what is listed on the left dropdown list

Nuxeo guys are having more and more projects listed on the welcome page which is not suitable when we are at a customer and which is a problem on Webinars, etc...

We should withdraw the list in the middle of the page, and use this query to fill the content of the projects' dropdown list (which currently displays all the projects when you are a Nuxeoer)