Fix problem with system sending empty answers

Some web browsers do not trigger the keyup or keydown events.
One of those web browsers is BluStar Agent.
This caused the system to think nothing had been entered into the fields.

Solve this problem by both listenting to change and keyup event.
Merge branch 'hotfix-send-empty-answer' into release-3.8.0
Merge branch 'release-3.8.0'