updates to DataTables and grid mfd mgmt

src/org/opensha2/calc/CalcConfig.java

src/org/opensha2/calc/Calcs.java

src/org/opensha2/calc/GridCalc.java

src/org/opensha2/calc/HazardCurveSet.java

src/org/opensha2/calc/HazardResult.java

src/org/opensha2/calc/Results.java

src/org/opensha2/data/DataTable.java

src/org/opensha2/data/DataVolume.java

src/org/opensha2/data/Interpolate.java

src/org/opensha2/data/XyPoint.java

src/org/opensha2/data/XySequence.java

src/org/opensha2/eq/model/GridParser.java

src/org/opensha2/eq/model/GridSourceSet.java

src/org/opensha2/eq/model/GridSourceSetTable.java

src/org/opensha2/eq/model/PointSource.java

test/etc/SequenceBenchmark.java