investigate whether a round-robin active scheduler could be implemented and used to benefit Qt application behaviour

With strict active object priority, first-in-first-served scheduling, it is fairly easy for an active object to exclude other active objects from running. This has been a significant problem in Qt apps, and the current implementation of the Qt event loop for Symbian does quite a lot of work to reschedule active objects so that they run in a round-robin fashion.

Rather than adding ever more complexity to the Qt event loop, we should investigate the benefits of having an active scheduler that schedules AOs in a round-robin style, possibly with soft priorities too. Then we can build a case for having the Symbian kernel enhance the OS provided scheduler, and investigate ways to support such a change on older platforms.