This keeps a coarser-grained `toplevel` property rather than `user`
and `session`. It also synthesizes a `streams` field within it with ids.
This makes it easier to put the streams in the URL by id.
(and various other lockfile upgrades. "npm audit" is clean.)
The date picker to use with 4.0 is unmaintained, and the new one is
apparently quite different.
Given that 5.0 is expected to be released this quarter, I prefer to
jump straight to the new one and get things working with it, even if
it means using an alpha in the short-term.
Scott Lamb