refactor(server): Move cdf and histogram processing into streams.
refactor(server): Stream all the data and calculations!
refactor(server): daily hits show again.

* Need to pass the start and end dates to hits_per_day on the setup to reduceStream
fix(server): ensure the referrers are shown in GET-site-localhost.js

* Referrer data is non-numeric and must be stored in ThinkStats.