Merge branch 'master' into develop
Fix casing issue with sourcetypes, addresses DVPL-3640
Update changelog to reflect changes to sourcetype casing issue for modular inputs
Fix sourceType -> sourcetype in modinput test data
Update changelog: fixed modinput test data
Add data model collection and stubbed out classes.
Add Field, DataModel, DataModelObject, and some more test data.
Added constraint class.
Started adding calculations.
Finished implementing calculation subclasses.
DataModel metadata and fetching objects done.

Partial implementation of acceleration methods on DataModel.
Finished implementing field. More progress on DataModelObject.
Finished implementing DataModelObject, Constraint, and Calculation.
Implemented subtypes of DataModelObject.
First messings around for pivot.
More pivot work. Updated all unit tests to JUnit 4 style.
Implemented pivot filters.
Implemented row splits for pivots.
Implemented pivot column splits.
Finished cell values, and started implementing pivot method.