do not show category drop down when no tags available, fix style, change button background when selected

For keeping the active filter is now saved in a variable.

This reverts merge request !321

change questionwall icon, add person icon to questions, display answer, add questionwall button i18n

fix routing bug, create simple style, like/dislike comments, comment timer, add ars-lib button icons

Differentiate between un/read comments, toggle: autofocus incoming comments, focus next/prev comment, update incoming comments