SQOOP-1898: Change the API of getJars to use SET than LIST to avoid duplicate jars

(Veena Basavaraj via Jarek Jarcec Cecho)
SQOOP-1783: Sqoop2: Create derby integration upgrade tests

(Jarek Jarcec Cecho via Abraham Elmahrek)
SQOOP-1897: Sqoop2: Submission Engine API change for better performance

(Veena Basavaraj via Abraham Elmahrek)
SQOOP-1755: Sqoop2: Security guide

(Richard Zhou via Abraham Elmahrek)
SQOOP-1879: Sqoop2: Convert the List in Schema Columns to Array for better lookup time

(Veena Basavaraj via Abraham Elmahrek)