Addition of Mike J's ClimateR-catalog
some changes to CatalogItem from pre-commit, changed masked_average to masked_mean in examples, due to Augusts stats change. Added ClimRCatData class to facilitate using Mike J's ClimateR-catalog
some changes to CatalogItem from pre-commit, changed masked_average to masked_mean in examples, due to Augusts stats change. Added ClimRCatData class to facilitate using Mike J's ClimateR-catalog