Work in progress. Moving PlotUtil static method to TimeSeriesCollection instance method.
Updating reduce so that it accesses a property of the object.
Updating usages of PlotUtils.getDataSplitIntoCurrentAndPreviousYears
Moved todo comments to NAWQAAN-373.
Minor fixes for tests.
Merge pull request #283 from cschroed-usgs/NAWQAAN-237-duplicatePlotsInTree

Nawqaan 237 duplicate plots in tree