[Ticket: #717]

During the last meeting, some problems were pointed out.
This commit should fix some of them.

Some UI bugs were discovered during a meeting, this is
a recommendation / example for new colors and fixing the bugs.

[Ticket: #219]

receive data on the questionwall is now from the room-data-service; Fix bugs on filtering the profanity

Also improved performance.

[Ticket: #109]

Ticket: #109

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