SPARK-1144 Added license and RAT to check licenses.

Author: Prashant Sharma <prashant.s@imaginea.com>

Closes #125 from ScrapCodes/rat-integration and squashes the following commits:

64f7c7d [Prashant Sharma] added license headers.
fcf28b1 [Prashant Sharma] Review feedback.
c0648db [Prashant Sharma] SPARK-1144 Added license and RAT to check licenses.
set hadoop task properties while using InputFormat

we should keep jobId consistent
style fix
style fix
move configuration for jobConf to HadoopRDD
update the comments and permission of SparkHadoopWriter
code cleanup
move SparkHiveHadoopWriter to org.apache.spark package