ported CompactingHashTable + unit tests to current master
Add LocalCollectionOutputFormat for local executor
JDBC InputFormat and OutputFormat for new Java API
Created TupleBuilder for every Tuple, via TupleGenerator
integrated CompactingHashTable in iterations code
Added JavaDocs for DataSet and Grouping
cleanup + documentation
Allow .yml file extension for config files (fixes #645)
Make delta iterations use Keys.FieldPositionKeys
Speed up execution by having an early heartbeat
Add support for serializing null strings.
Fix bug in binary copying of long strings.
Add tests for string serialization.
Add base utility for serializer tests.
Add string array serializer with test.
intermediate (new hashtable and broken joinwithsolutionset*driver)
cogroup fixed
match fixed but ConnectedComponentsWithDeferredUpdateITCase still fails
Added Grouping unit test, extended Reduce integration test, added JavaDocs to ReduceFunction
Preliminary support for String arrays in new Java API
Improve error messages for instantiation errors on arrays and for programs without data sinks.
Add write mode to data set write function.