added try/catch block to catch unused session is hasStackedData()

added prefixes on all css classes (fixed php-debugbar#35)

using images for close and open icons instead of font-awesome
using time instead of datetime in dataset selection box

updated docs [ci skip]

removed usage of session_status()

fixed the bug where the debug bar obscures page content (fixed php-de…

…bugbar#10)

updated README

added setOptions() in JavascriptRenderer

updated docs and README

fixed bug with unknown tab when restoring state

updated doc