Make statistics tasks smarter and only calculate diff for the last day.

This avoids "since the beginning of time" queries. It does rely on tasks for
yesterday to succeed and have an uninterrupted sequence of results.
add the first cuts for a new map prototype
leaflet doesn't like protocol relative urls
increase max zoom level for new map
decrease log output from beat process (no longer log every task invocation)
filter out -1 values for lac and cid when doing a search by Cell record
added extra filtering so that CellMeasures with lac and cid = -1, are ignored