[FLINK-1324] [runtime] Trailing data is cached before the local input strategies are closed.
[FLINK-1322] Make Scala API respect WriteMode set in Config

This closes #266
[scala] Change ScalaAggregateOperator to use TypeSerializer

This closes #263
[misc] Fix/suppress various compiler warnings.
[FLINK-1305] [FLINK-1304] Test for HadoopInputWrapper and NullWritable support

This closes #252