Headers and test for machine-readable outputs from measures. [#59977728]
Making flat json serialization for std::vector<Attribute>. Is just a different serialization than the one for a single Attribute ... Is mildly lossy. [#59977728]
Machine readable results feature passes test. [#59977728]
Merge pull request #795 from NREL/20140108_ETH_AddMachineReadableOutputsToMeasures_59977728

20140108 eth add machine readable outputs to measures 59977728