Allow using Ajax for tab switching

In default JSF UI, Tab switching is done via a REST navigation that reloads the whole page.

Thanks to all the infrastructure imrpovements, this is very easy to change to have Ajax tab switching and this really improves the Look and Feel :

• switch is faster (especially visible when accesskey shortcuts is used)
• this make the tab system look more real

In addition, this should really require less work on the server side and make the app scale better (to be validated by Ben

The only drawback of Ajax tab switching is that URL is not longer restful.

Hopefuly with recent browser and Html5, we can use history.pushState to update the URL with the Ajax update has been done.

However, we must be careful about :

• Ajax calls serialization (queuing) to avoid any crashes
• Selenium and Funkload tests updates

We also need to define if Ajax Switching should be activated by default and for all browser.

Initial implementation will probably use a system property to activate Ajax and we'll see when all the tests are ok.