IMPALA-1142: Support specifying a custom AuthorizationProvider in Impala

This change allows Impala to support specifying a custom AuthorizationProvider class
(rather than the default HadoopGroupAuthorizationProvider). One use case is using the
LocalGroupAuthorizationProvider which makes it easier to test different users without
them actually existing and also allows Sentry be enabled without creating the groups
on all nodes the cluster. This is something we used to support but deprecated in
v1.4-cdh5 release. Added back in the changes and extended tests.

Change-Id: I09612e4e331689402f8f05d2666b3de61d881529
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3868
Tested-by: jenkins
Reviewed-by: Nong Li <nong@cloudera.com>
Cleanup a few comments.

Change-Id: Ia2e2d6e4e1e0a5d2ab0b8ded551bb8a8949ce84a
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3911
Reviewed-by: Henry Robinson <henry@cloudera.com>
Tested-by: Daniel Hecht <dhecht@cloudera.com>
Optimize Regex patterns with constant substrings.

Performance example: using tpch_parquet database

Constant string:
select count(*) from line item where l_shipinstruct REGEXP “^DELIVER IN PERSON$”;
4.22s -> 3.62s

Constant substring:
select count(*) from lineitem where l_shipinstruct REGEXP “IN”;
5.03s -> 4.12

Constant substring at beginning:
select count(*) from lineitem where l_shipinstruct REGEXP “^DELIVER”;
4.22s -> 3.82s

Constant substring at end:
select count(*) from line item where l_shipinstruct REGEXP “PERSON$”;
5.02 -> 3.83

Change-Id: Id1aa0511b023df6ef88678f2ecf5f348d5da3597
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3829
Reviewed-by: Paden Tomasello <paden.tomasello@cloudera.com>
Tested-by: jenkins
Add a summary page to query table

This commit adds a summary page for each completed query which displays
the query statement, the query state, the plan and the execution summary.

Change-Id: I9739f1a2ddd1d6465a69d59bb3f173b0101e6fe8
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3645
Reviewed-by: Henry Robinson <henry@cloudera.com>
Tested-by: jenkins