If error is not displayed in web browser then
it will be caught in shutdown hook, so we can
show it to user

If the user cannot subscribe, there is no point showing the digest options.

Daily digest options should not be generated if the user cannot subscribe
to anything in the first place.

Added an upgrade step to remove duplicate stamps, added a unique index
on (contextid, stamp) and modified the question_category edit code such
that stamp duplication in the same context is not permitted.

In a Workshop activity, comment fields on Assessment forms do not properly link to the corresponding Aspect.
So screen reader users may find it difficult to complete the Assessment forms.
There should be a hidden label text for each comment field.

Delete tablesupdatedbyscenario before db reset to ensure
db is fully reset. In case user exits or process terminated
then the file will be left and can lead to wrong results

Fixed a call to get_records_sql, which was being used incorrectly in
restore_find_best_target_context to determine a unique contextid.

Old settings that should be ignored have been removed from the
statistics cron code.