Jebeck/modal day

First pass at integration of modal day into blip. Depends on https://github.com/tidepool-org/tideline/pull/189 and https://github.com/tidepool-org/sundial/pull/11.

Ready for review. Ping: @nicolashery @ianjorgensen 

Because I needed to add some new sundial functions, I also had to update the message components to the new 1.x version of sundial. I would also *like* to remove the moment dependency that was (re)introduced recently (by replacing with sundial and/or adding new sundial functions where necessary), but strictly speaking that's not necessary at this point in time. @nicolashery maybe we should discuss?
"I one to reduce the extent by half"? :wink: