Fixes #4950: move node quicksearch to top-right of rudder

Move the node quicksearch field to top right of Rudder. 
Take the occasion to clean the nodeSearch page: now, a node details is always displayed from an ajax call. 
Also, that ajax call is ALWAYS triggered from the "on hashchange" event, which is now supported for a long time (IE8, Chrome 5, FF3.6, etc). That simplifies a lot the logic of the page. 

The stilling was a little ****** to get right.