Bulk Operation

SPARK-17924 Move `SparkHadoopWriter` to `internal/io/`

SPARK-17924 Implement commit protocol to support `mapred` package's committer

SPARK-17924 Move commit protocol API from sql to core module

SPARK-17924 Support all file formats in structured streaming

SPARK-17924 Port RDD API to use commit protocol

SPARK-17924 OutputWriter needs to return the path of the file written

SPARK-17924 Port streaming to use the commit protocol API

SPARK-17924 Introduce an internal commit protocol API along with OutputCommitter implementation

SPARK-17924 Refactor file name specification for data sources

SPARK-17924 Simplify WriterContainer code

SPARK-17924 Remove dead code in WriterContainer

SPARK-17924 Break fileSourceInterfaces.scala into multiple pieces