Merge pull request #138 from graydon/add-metrics-for-dropped-items

Add metrics for items dropped due to trim_excessive task
Merge pull request #139 from graydon/more-measure-ingress-metrics

A few more items.* metrics, and move uploaded to uploaded.batches.
Show 60 days of history in the cell/wifi graphs.
WIP on adding cell blacklisting, ref #134; don't merge yet