Add TRole/TPrivilege structs to Thrift CatalogObjects

These are used as our internal representation of the authorization policy metadata
(as opposed to directly using the Sentry Thrift structs). Versioned/managed in the
same way as other TCatalogObjects.

Change-Id: Ia1ed9bd4e25e9072849edebcae7c2d3a7aed660d
Reviewed-on: http://gerrit.ent.cloudera.com:8080/2545
Reviewed-by: Lenni Kuff <lskuff@cloudera.com>
Tested-by: jenkins
Address CR comments on HdfsAvroScanner.

Change-Id: Ia92b07e0b0cd16297c0d84f0df5e5eff76788c3e
Reviewed-on: http://gerrit.ent.cloudera.com:8080/2610
Reviewed-by: Marcel Kornacker <marcel@cloudera.com>
Tested-by: jenkins
IMPALA-984: Fix missing reanalyze in InlineViewRef and NULL handling.

Change-Id: Ia80035c5456630aeef7a24288a998fe08546a282
Reviewed-on: http://gerrit.ent.cloudera.com:8080/2628
Reviewed-by: Nong Li <nong@cloudera.com>
Tested-by: jenkins