SQOOP-1775: Sqoop2: Migrate to URL parameter user.name instead of using header

(Abraham Elmahrek via Jarek Jarcec Cecho)
SQOOP-1792: Sqoop2: Default to simple authentication type

(Abraham Elmahrek via Jarek Jarcec Cecho)
SQOOP-1784: Sqoop2: Sending POST request to link or job end-point might end up with NPE

(Jarek Jarcec Cecho via Abraham Elmahrek)