Changed ui of preview button to "action".
Changed badges according to Task #12846.
Changed flashcard preview button ui to 'action'.
Several changes concerning flashcard question form.
Changed margins of all question options in newQuestionPanel.
Removed bold font-weight from several text elements.
Changed button text of picture question.
Changed abstention button ui to 'action'.
Reconstructed askPanel formfields, buttons and fieldsets
Recolored carousel indicators.
Changed inactive session/question text to thm-red.
Changed list selection color to thm-orange.
Removed bold font-weight from THM link and added more top-margin.
Added ios icon from arsnova overlay; removed loading image.
Removed unneeded images.
Changed unread feedback question color to thm-red.