HIVE-7556: Fix code style, license header, tabs, etc. [Spark Branch]

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/spark@1614747 13f79535-47bb-0310-9956-ffa450edef68
HIVE-7564: Remove some redundant code plus a bit of cleanup in SparkClient [Spark Branch]

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/spark@1614800 13f79535-47bb-0310-9956-ffa450edef68