Resolving bug #576.

Resolving bug #576.
This solution shows the message "Recently added question!" and the question text for each question that has been added since the reviewed attempt.
The advantage with the chosen solution is that it will work fine for the (soon to come) "Each attempt builds on the last" quiz option.

As I don't have the karma needed for updating in lang/en/, the message does not yet look quite as I described it above.