All sink methods in DataSet return the DataSink object to allow setting parameters.
Improved error message in PackagedProgram for preview plans.
Fixed pre-packaged end-to-end test.
Add projection cross
Minor fixes in JavaDocs and parameter checks
Unit tests to check for valid parameters of cogroup
Activated unit test for CoGroupOperator
Default cross operator
Combinable GroupReduce for new Java API
Changed key handling for key-selector combiners