jsroot: i/o Add unique stamp parameter in file url to avoid cashing on the browser, solves problem with Chrome

Signed-off-by: Bertrand Bellenot <bertrand.bellenot@cern.ch>
jsroot: 1. Use preserveAspectRation in SVG drawing to handle small resizes of browser, only when resize goes over factor 2 complete redraw will be done 2. New separator between browser and display area, implemented with jQuery Draggable class 3. Display JSROOT.version in other place, save 17 pixels for drawings

Signed-off-by: Bertrand Bellenot <bertrand.bellenot@cern.ch>
http: Set "Cache-Control" header in most reply headers to prevent browser from caching of temporary data

Signed-off-by: Bertrand Bellenot <bertrand.bellenot@cern.ch>
jsroot: update docu

Signed-off-by: Bertrand Bellenot <bertrand.bellenot@cern.ch>