Disable analytic fn query tests for avro

Avro doesn't support a timestamp type and the analytic fn tests
need to exercise avg() for timestamps because there's a template
specialization of the avg() UDA for timestamps. It's less
important right now to test on avro because the analytic function
evaluation is unlikely to be affected by file formats. There is
a TODO to enable some of the tests for avro later, if possible.

Change-Id: I5d69816cc0864deab4cf01b6a5969d39cec8875a
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/4238
Reviewed-by: Alex Behm <alex.behm@cloudera.com>
Reviewed-by: Matthew Jacobs <mj@cloudera.com>
Tested-by: Matthew Jacobs <mj@cloudera.com>
IMPALA-1195: IllegalStateException in query with agg scalar subquery

This commit fixes IMPALA-1195 in which an exception is thrown when a
scalar subquery is in an IS NULL predicate. With this commit we also add
support for scalar subqueries in functions and other exprs.

Change-Id: Id995e77e6561a6450c4347706e4901fb3e236cfe
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/4185
Reviewed-by: Dimitris Tsirogiannis <dtsirogiannis@cloudera.com>
Tested-by: Dimitris Tsirogiannis <dtsirogiannis@cloudera.com>
Catch exception on Thrift client close()

Thrift's close() may call flush(), which calls write(), which may
throw. This patch catches that exception, logs and then ignores it.

Change-Id: I4952de1836531671546676ede40456e391b7c0d5
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/4214
Reviewed-by: Daniel Hecht <dhecht@cloudera.com>
Tested-by: Henry Robinson <henry@cloudera.com>
IMPALA-1104: Fixes for compute stats on Avro tables. Create Avro tables without col defs.

This patch addresses the following issues:
1. Allow creating Avro tables without col defs in Impala. Compute stats works on them.
2. Handle table creation with inconsistent col defs and Avro schema as follows:
   The table creation will succeed and ignore the col defs in favor of the Avro schema.
   A warning is issued that the col defs and the Avro schema are inconsistent.
   Compute stats works on such tables.

This patch does not address the issue of compute stats after Avro schema evolution.

Change-Id: Iea6b737d238d81491dc2097012ebc149a89d03ba
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/4182
Reviewed-by: Alex Behm <alex.behm@cloudera.com>
Tested-by: Alex Behm <alex.behm@cloudera.com>