MEDIUM: queue: adjust position based on priority-class and priority-offset

MEDIUM: queue: adjust position based on priority-class and priority-offset

The priority values are used when connections are queued to determine
which connections should be served first. The lowest priority class is
served first. When multiple requests from the same class are found, the
earliest (according to queue_time + offset) is served first. The queue
offsets can span over roughly 17 minutes after which the offsets will
wrap around. This allows up to 8 minutes spent in the queue with no
reordering.