#8: Collect and output metrics about changed files in metrics-history

Currently metrics-history only collects metrics statistics, ignoring individual module metrics. metrics-batch can do both, but outputs metrics for all modules. It's more useful to just output metrics about files that changed between the current iteration and the logically previous one, e.g. we only need to output the metrics values that actually changed!

This behaviour must be consolidated, probably using the common framework for batch operations (7)

-- AntonioTerceiro - 02 Jun 2011

Note to self: look at draft requirements on paper

-- AntonioTerceiro - 09 Jun 2011

This actually only makes sense for `metrics-history`, not for `metrics-batch`.

-- AntonioTerceiro - 05 Aug 2011

This actually does not make sense since the only output currently available for metrics-history is the CSV output, in which we cannot vary the output for individual items. See 9 instead.

-- AntonioTerceiro - 05 Aug 2011