Users who could not manage activities on a course, but did have
permission to access particular question banks, could not access the
Question banks page.
This modifies the permission checks on that page to allow access if the
user can either manage activities, or has access to at least one
activity that publishes questions. Some additional changes to the output
were required to prevent non-editing users adding banks.
It also modifies the navigation hook to add the Question banks
navigation node if the user can access any activitiy that publishes
questions on the course. This is all based on cached modinfo and
permissions data so should remain performant.
Mark Johnson
fbf2963387