Removed some obsolete code
Created panel to select the exact amount of answer options
Fixed #6556: Implemented ABCD questions just like MC

There's one caveat, though: now it is possible to elect multiple
correct answers, but the students may still only choose on answer.
Multiple correct answers to choose from could be considered a
feature -- or a bug.
Fixed showcase view in Firefox
Fixed question view for Firefox
Fixed #6391: Added proper i18n for date & time
Fixed error while swiping
Fixed #6555: Show basic error message if used w/ wrong browser
Forgot to delete console.log :-(
Changed handling of raw websocket events
Feedback chart is updated by web socket events
Removed obsolete methods
Removed more feedback polling

These changes make some design problems evident. There is much
duplication present across all "TabPanels". These have to get
removed at some later time.
After answering all questions the active item will be set to
user.InClass panel (Task #6557). In order to establish a proper carousel
flow a further feature has been added. For instance question two and
three has been answered and only answer one is unanswered, then answer
one will be set as next answer instead of just disable the carousel.
Merge remote-tracking branch 'origin/master'
Removed more obsolete methods
Merge branch 'feedback-websockets'

Revert this commit if anything bad happens.
Replaced CSS height property by min-height for feedback smiley buttons
to fix height problem in FF22.
Issue #6403: Display locked sessions in red
Fixed #6403: Locked questions are displayed in red as well.