Added LZ4 to compression codec in configuration page.

Author: Reynold Xin <rxin@apache.org>

Closes #1417 from rxin/lz4 and squashes the following commits:

472f6a1 [Reynold Xin] Set the proper default.
9cf0b2f [Reynold Xin] Added LZ4 to compression codec in configuration page.
[SPARK-2471] remove runtime scope for jets3t

The assembly jar (built by sbt) doesn't include jets3t if we set it to runtime only, but I don't know whether it was set this way for a particular reason.

CC: srowen ScrapCodes

Author: Xiangrui Meng <meng@databricks.com>

Closes #1402 from mengxr/jets3t and squashes the following commits:

bfa2d17 [Xiangrui Meng] remove runtime scope for jets3t
[SPARK-2483][SQL] Fix parsing of repeated, nested data access.

Author: Michael Armbrust <michael@databricks.com>

Closes #1411 from marmbrus/nestedRepeated and squashes the following commits:

044fa09 [Michael Armbrust] Fix parsing of repeated, nested data access.
[SQL] Whitelist more Hive tests.

Author: Michael Armbrust <michael@databricks.com>

Closes #1396 from marmbrus/moreTests and squashes the following commits:

6660b60 [Michael Armbrust] Blacklist a test that requires DFS command.
8b6001c [Michael Armbrust] Add golden files.
ccd8f97 [Michael Armbrust] Whitelist more tests.
[SPARK-2474][SQL] For a registered table in OverrideCatalog, the Analyzer failed to resolve references in the format of "tableName.fieldName"

Please refer to JIRA (https://issues.apache.org/jira/browse/SPARK-2474) for how to reproduce the problem and my understanding of the root cause.

Author: Yin Huai <huai@cse.ohio-state.edu>

Closes #1406 from yhuai/SPARK-2474 and squashes the following commits:

96b1627 [Yin Huai] Merge remote-tracking branch 'upstream/master' into SPARK-2474
af36d65 [Yin Huai] Fix comment.
be86ba9 [Yin Huai] Correct SQL console settings.
c43ad00 [Yin Huai] Wrap the relation in a Subquery named by the table name in OverrideCatalog.lookupRelation.
a5c2145 [Yin Huai] Support sql/console.
SPARK-2407: Added internal implementation of SQL SUBSTR()

This replaces the Hive UDF for SUBSTR(ING) with an implementation in Catalyst
and adds tests to verify correct operation.

Author: William Benton <willb@redhat.com>

Closes #1359 from willb/internalSqlSubstring and squashes the following commits:

ccedc47 [William Benton] Fixed too-long line.
a30a037 [William Benton] replace view bounds with implicit parameters
ec35c80 [William Benton] Adds fixes from review:
4f3bfdb [William Benton] Added internal implementation of SQL SUBSTR()
[SQL] Attribute equality comparisons should be done by exprId.

Author: Michael Armbrust <michael@databricks.com>

Closes #1414 from marmbrus/exprIdResolution and squashes the following commits:

97b47bc [Michael Armbrust] Attribute equality comparisons should be done by exprId.
[SPARK-2498] [SQL] Synchronize on a lock when using scala reflection inside data type objects.

JIRA ticket: https://issues.apache.org/jira/browse/SPARK-2498

Author: Zongheng Yang <zongheng.y@gmail.com>

Closes #1423 from concretevitamin/scala-ref-catalyst and squashes the following commits:

325a149 [Zongheng Yang] Synchronize on a lock when initializing data type objects in Catalyst.
[SPARK-2469] Use Snappy (instead of LZF) for default shuffle compression codec

This reduces shuffle compression memory usage by 3x.

Author: Reynold Xin <rxin@apache.org>

Closes #1415 from rxin/snappy and squashes the following commits:

06c1a01 [Reynold Xin] SPARK-2469: Use Snappy (instead of LZF) for default shuffle compression codec.
[SPARK-2500] Move the logInfo for registering BlockManager to BlockManagerMasterActor.register method

PR for SPARK-2500

Move the logInfo call for BlockManager to BlockManagerMasterActor.register instead of BlockManagerInfo constructor.

Previously the loginfo call for registering the registering a BlockManager is happening in the BlockManagerInfo constructor. This kind of confusing because the code could call "new BlockManagerInfo" without actually registering a BlockManager and could confuse when reading the log files.

Author: Henry Saputra <henry.saputra@gmail.com>

Closes #1424 from hsaputra/move_registerblockmanager_log_to_registration_method and squashes the following commits:

3370b4a [Henry Saputra] Move the loginfo for BlockManager to BlockManagerMasterActor.register instead of BlockManagerInfo constructor.
follow pep8 None should be compared using is or is not

http://legacy.python.org/dev/peps/pep-0008/
## Programming Recommendations
- Comparisons to singletons like None should always be done with is or is not, never the equality operators.

Author: Ken Takagiwa <ken@Kens-MacBook-Pro.local>

Closes #1422 from giwa/apache_master and squashes the following commits:

7b361f3 [Ken Takagiwa] follow pep8 None should be checked using is or is not
[SPARK-2314][SQL] Override collect and take in JavaSchemaRDD, forwarding to SchemaRDD implementations.

Author: Aaron Staple <aaron.staple@gmail.com>

Closes #1421 from staple/SPARK-2314 and squashes the following commits:

73e04dc [Aaron Staple] [SPARK-2314] Override collect and take in JavaSchemaRDD, forwarding to SchemaRDD implementations.
Merge remote-tracking branch 'upstream/master'