Hive improvements

A number of hive improvements:
* Ability to set performance options for hive queries
* Removed the unused hive conf from the sources.
* Ability to create external tables.

/cc @SamRoberts @tims 
sorry I meant in file hive/src/main/scala/au/com/cba/omnia/ebenezer/scrooge/hive/PartitionHiveParquetScroogeSource.scala