Exclude docs/_site/** from License Check
[FLINK-1287] LocalizableSplitAssigner prefers splits with less degrees of freedom

This closes #258
[FLINK-1208] Enable CsvInputFormats to ignore invalid lines and lines starting with comments

This closes #201
[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
[FLINK-1307] Allow file input from nested directory structure

This closes #260
[FLINK-1307] Excluded directories that match the file-filter from recursive descent.