When I tried this before threading was working better.
Now asyncio is doing better.
Recently, exceptions were happening occasionaly in the update
thread. I guess due to races. They should go away now.
From now on, if a coroutine takes too long the interface will hitch.
Should investigate if sync_to_filesystem is taking too long and
if it can yield.
There are no uses of threading now.
I was having problems with the old scheme.
Now you use tab to switch focus between the summary and result
panes. The keys to navigate are the same in both places.
