Ianjorgensen/lollipop

@jebeck  Finished moving the branch. Ready for review.
Catching some more things while updating the viz tests for lollipops. You're missing the `QUARTER` etc. constants (need to be copied, or better yet factored out, from `js/plot/bolus`).

Would be great to factor the `timespan` function and accompanying constants into `js/data/util/datetime`.