HIVE-4171 - Hive  class comment
HIVE-4171 - update hive class comment
adding currentDatabase private member to SessionState
adding ss get/set current db
Replacing calls to Hive.getCurrentDb
Updating QTestUtil getcurrentdb
removing unused stmt
doing ss.start in more tests
fix compile
Return default db if not set
ss.start in additional tests
ss.start in additional tests
adding TestSessionState
test cosmetic updates
changes to new hcat files
Fix unit test failures