Adds Apache License Headers, enables rat-check, find-bugs and checkstyle plugins. Contributed by Venkatesh Seetharam

Fixed hive model: StorageDescription is now a class, removed creating a duplicate storagedesc per partition (need to fix handling of partitions that can diverge).
  Made mem repository test work again.
Validated changes with TPCDS.  Fixed empty array handling in Graph repo

Adds Apache License Headers, enables rat-check, find-bugs and checkstyle plugins. Contributed by Venkatesh Seetharam

service is now loaded correctly.

Fix Hive Importer to work with Graph repository and needed refactoring.   Also fix enum handling in the repository

Added columns into table and partition classes as there are no back references to table/partition from column classes