Fixed bug#4453: summary table scrolling is too slow.
Tracked down but#8977:Calendar view has wonky geometry after restart on Windows for Jeffrey
Researched rare failures of recorded tests, but still don't understand the source of the problem.
I embarked on getting rid of DynamicContainers?, which we think will yield a big performance improvement. It also gets rid of boat loads of code and the new code will be much easier to understand. It also involves serious refactoring of toolbars and menus, which will with some luck yield a simple solution to the "calclulated menu" feature. It's a risky change, so I may or may not be able to pull it off, but hopefully I'll know whether or not it will work in a few days.