Merge pull request #4066 from RosettaCommons/jadolfbr/mmTF
With Dan Farrell's gracious help, this PR allows extra data to be output and read back in for mmTF. For SimpleMetrics, this allows basic multi-run protocols to keep important data around (that could also be used for a subsequent jobs like filtering), and leads the way for a multistage implementation using mmTF.
This PR includes a full round-trip unit test suite for the extra data.