[SPARK-2097][SQL] UDF Support

This patch adds the ability to register lambda functions written in Python, Java or Scala as UDFs for use in SQL or HiveQL.

Scala:
```scala
registerFunction("strLenScala", (_: String).length)
sql("SELECT strLenScala('test')")
```
Python:
```python
sqlCtx.registerFunction("strLenPython", lambda x: len(x), IntegerType())
sqlCtx.sql("SELECT strLenPython('test')")
```
Java:
```java
sqlContext.registerFunction("stringLengthJava", new UDF1<String, Integer>() {
  Override
  public Integer call(String str) throws Exception {
    return str.length();
  }
}, DataType.IntegerType);

sqlContext.sql("SELECT stringLengthJava('test')");
```

Author: Michael Armbrust <michael@databricks.com>

Closes #1063 from marmbrus/udfs and squashes the following commits:

9eda0fe [Michael Armbrust] newline
747c05e [Michael Armbrust] Add some scala UDF tests.
d92727d [Michael Armbrust] Merge remote-tracking branch 'apache/master' into udfs
005d684 [Michael Armbrust] Fix naming and formatting.
d14dac8 [Michael Armbrust] Fix last line of autogened java files.
8135c48 [Michael Armbrust] Move UDF unit tests to pyspark.
40b0ffd [Michael Armbrust] Merge remote-tracking branch 'apache/master' into udfs
6a36890 [Michael Armbrust] Switch logging so that SQLContext can be serializable.
7a83101 [Michael Armbrust] Drop toString
795fd15 [Michael Armbrust] Try to avoid capturing SQLContext.
e54fb45 [Michael Armbrust] Docs and tests.
437cbe3 [Michael Armbrust] Update use of dataTypes, fix some python tests, address review comments.
01517d6 [Michael Armbrust] Merge remote-tracking branch 'origin/master' into udfs
8e6c932 [Michael Armbrust] WIP
3f96a52 [Michael Armbrust] Merge remote-tracking branch 'origin/master' into udfs
6237c8d [Michael Armbrust] WIP
2766f0b [Michael Armbrust] Move udfs support to SQL from hive. Add support for Java UDFs.
0f7d50c [Michael Armbrust] Draft of native Spark SQL UDFs for Scala and Python.
[SPARK-2785][SQL] Remove assertions that throw when users try unsupported Hive commands.

Author: Michael Armbrust <michael@databricks.com>

Closes #1742 from marmbrus/asserts and squashes the following commits:

5182d54 [Michael Armbrust] Remove assertions that throw when users try unsupported Hive commands.
[SPARK-2729][SQL] Added test case for SPARK-2729

This is a follow up of #1636.

Author: Cheng Lian <lian.cs.zju@gmail.com>

Closes #1738 from liancheng/test-for-spark-2729 and squashes the following commits:

b13692a [Cheng Lian] Added test case for SPARK-2729
[SPARK-2797] [SQL] SchemaRDDs don't support unpersist()

The cause is explained in https://issues.apache.org/jira/browse/SPARK-2797.

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

Closes #1745 from yhuai/SPARK-2797 and squashes the following commits:

7b1627d [Yin Huai] The unpersist method of the Scala RDD cannot be called without the input parameter (blocking) from PySpark.
[SPARK-2739][SQL] Rename registerAsTable to registerTempTable

There have been user complaints that the difference between `registerAsTable` and `saveAsTable` is too subtle.  This PR addresses this by renaming `registerAsTable` to `registerTempTable`, which more clearly reflects what is happening.  `registerAsTable` remains, but will cause a deprecation warning.

Author: Michael Armbrust <michael@databricks.com>

Closes #1743 from marmbrus/registerTempTable and squashes the following commits:

d031348 [Michael Armbrust] Merge remote-tracking branch 'apache/master' into registerTempTable
4dff086 [Michael Armbrust] Fix .java files too
89a2f12 [Michael Armbrust] Merge remote-tracking branch 'apache/master' into registerTempTable
0b7b71e [Michael Armbrust] Rename registerAsTable to registerTempTable
SPARK-2602 [BUILD] Tests steal focus under Java 6

As per https://issues.apache.org/jira/browse/SPARK-2602 , this may be resolved for Java 6 with the java.awt.headless system property, which never hurt anyone running a command line app. I tested it and seemed to get rid of focus stealing.

Author: Sean Owen <srowen@gmail.com>

Closes #1747 from srowen/SPARK-2602 and squashes the following commits:

b141018 [Sean Owen] Set java.awt.headless during tests
SPARK-2414 [BUILD] Add LICENSE entry for jquery

The JIRA concerned removing jquery, and this does not remove jquery. While it is distributed by Spark it should have an accompanying line in LICENSE, very technically, as per http://www.apache.org/dev/licensing-howto.html

Author: Sean Owen <srowen@gmail.com>

Closes #1748 from srowen/SPARK-2414 and squashes the following commits:

2fdb03c [Sean Owen] Add LICENSE entry for jquery
[Minor] Fixes on top of #1679

Minor fixes on top of #1679.

Author: Andrew Or <andrewor14@gmail.com>

Closes #1736 from andrewor14/amend-#1679 and squashes the following commits:

3b46f5e [Andrew Or] Minor fixes
SPARK-2712 - Add a small note to maven doc that mvn package must happen ...

Per request by Reynold adding small note about proper sequencing of build then test.

Author: Stephen Boesch <javadba@gmail.com>

Closes #1615 from javadba/docs and squashes the following commits:

6c3183e [Stephen Boesch] Moved updated testing blurb per PWendell
5764757 [Stephen Boesch] SPARK-2712 - Add a small note to maven doc that mvn package must happen before test
SPARK-2246: Add user-data option to EC2 scripts

Author: Allan Douglas R. de Oliveira <allan@chaordicsystems.com>

Closes #1186 from douglaz/spark_ec2_user_data and squashes the following commits:

94a36f9 [Allan Douglas R. de Oliveira] Added user data option to EC2 script
[SPARK-2197] [mllib] Java DecisionTree bug fix and easy-of-use

Bug fix: Before, when an RDD was created in Java and passed to DecisionTree.train(), the fake class tag caused problems.
* Fix: DecisionTree: Used new RDD.retag() method to allow passing RDDs from Java.

Other improvements to Decision Trees for easy-of-use with Java:
* impurity classes: Added instance() methods to help with Java interface.
* Strategy: Added Java-friendly constructor
--> Note: I removed quantileCalculationStrategy from the Java-friendly constructor since (a) it is a special class and (b) there is only 1 option currently.  I suspect we will redo the API before the other options are included.

CC: mengxr

Author: Joseph K. Bradley <joseph.kurata.bradley@gmail.com>

Closes #1740 from jkbradley/dt-java-new and squashes the following commits:

0805dc6 [Joseph K. Bradley] Changed Strategy to use JavaConverters instead of JavaConversions
519b1b7 [Joseph K. Bradley] * Organized imports in JavaDecisionTreeSuite.java * Using JavaConverters instead of JavaConversions in DecisionTreeSuite.scala
f7b5ca1 [Joseph K. Bradley] Improvements to make it easier to run DecisionTree from Java. * DecisionTree: Used new RDD.retag() method to allow passing RDDs from Java. * impurity classes: Added instance() methods to help with Java interface. * Strategy: Added Java-friendly constructor ** Note: I removed quantileCalculationStrategy from the Java-friendly constructor since (a) it is a special class and (b) there is only 1 option currently.  I suspect we will redo the API before the other options are included.
d78ada6 [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into dt-java
320853f [Joseph K. Bradley] Added JavaDecisionTreeSuite, partly written
13a585e [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into dt-java
f1a8283 [Joseph K. Bradley] Added old JavaDecisionTreeSuite, to be updated later
225822f [Joseph K. Bradley] Bug: In DecisionTree, the method sequentialBinSearchForOrderedCategoricalFeatureInClassification() indexed bins from 0 to (math.pow(2, featureCategories.toInt - 1) - 1). This upper bound is the bound for unordered categorical features, not ordered ones. The upper bound should be the arity (i.e., max value) of the feature.
[SPARK-2784][SQL] Deprecate hql() method in favor of a config option, 'spark.sql.dialect'

Many users have reported being confused by the distinction between the `sql` and `hql` methods.  Specifically, many users think that `sql(...)` cannot be used to read hive tables.  In this PR I introduce a new configuration option `spark.sql.dialect` that picks which dialect with be used for parsing.  For SQLContext this must be set to `sql`.  In `HiveContext` it defaults to `hiveql` but can also be set to `sql`.

The `hql` and `hiveql` methods continue to act the same but are now marked as deprecated.

**This is a possibly breaking change for some users unless they set the dialect manually, though this is unlikely.**

For example: `hiveContex.sql("SELECT 1")` will now throw a parsing exception by default.

Author: Michael Armbrust <michael@databricks.com>

Closes #1746 from marmbrus/sqlLanguageConf and squashes the following commits:

ad375cc [Michael Armbrust] Merge remote-tracking branch 'apache/master' into sqlLanguageConf
20c43f8 [Michael Armbrust] override function instead of just setting the value
7e4ae93 [Michael Armbrust] Deprecate hql() method in favor of a config option, 'spark.sql.dialect'
[SPARK-2814][SQL] HiveThriftServer2 throws NPE when executing native commands

JIRA issue: [SPARK-2814](https://issues.apache.org/jira/browse/SPARK-2814)

Author: Cheng Lian <lian.cs.zju@gmail.com>

Closes #1753 from liancheng/spark-2814 and squashes the following commits:

c74a3b2 [Cheng Lian] Fixed SPARK-2814
[SPARK-2783][SQL] Basic support for analyze in HiveContext

JIRA: https://issues.apache.org/jira/browse/SPARK-2783

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

Closes #1741 from yhuai/analyzeTable and squashes the following commits:

7bb5f02 [Yin Huai] Use sql instead of hql.
4d09325 [Yin Huai] Merge remote-tracking branch 'upstream/master' into analyzeTable
e3ebcd4 [Yin Huai] Renaming.
c170f4e [Yin Huai] Do not use getContentSummary.
62393b6 [Yin Huai] Merge remote-tracking branch 'upstream/master' into analyzeTable
db233a6 [Yin Huai] Trying to debug jenkins...
fee84f0 [Yin Huai] Merge remote-tracking branch 'upstream/master' into analyzeTable
f0501f3 [Yin Huai] Fix compilation error.
24ad391 [Yin Huai] Merge remote-tracking branch 'upstream/master' into analyzeTable
8918140 [Yin Huai] Wording.
23df227 [Yin Huai] Add a simple analyze method to get the size of a table and update the "totalSize" property of this table in the Hive metastore.
[SPARK-1740] [PySpark] kill the python worker

Kill only the python worker related to cancelled tasks.

The daemon will start a background thread to monitor all the opened sockets for all workers. If the socket is closed by JVM, this thread will kill the worker.

When an task is cancelled, the socket to worker will be closed, then the worker will be killed by deamon.

Author: Davies Liu <davies.liu@gmail.com>

Closes #1643 from davies/kill and squashes the following commits:

8ffe9f3 [Davies Liu] kill worker by deamon, because runtime.exec() is too heavy
46ca150 [Davies Liu] address comment
acd751c [Davies Liu] kill the worker when task is canceled
[SPARK-2810] upgrade to scala-maven-plugin 3.2.0

Needed for Scala 2.11 compiler-interface

Signed-off-by: Anand Avati <avatiredhat.com>

Author: Anand Avati <avati@redhat.com>

Closes #1711 from avati/SPARK-1812-scala-maven-plugin and squashes the following commits:

9a22fc8 [Anand Avati] SPARK-1812: upgrade to scala-maven-plugin 3.2.0
Fix some bugs with spaces in directory name.

Any time you use the directory name (`FWDIR`) it needs to be surrounded
in quotes. If you're also using wildcards, you can safely put the quotes
around just `$FWDIR`.

Author: Sarah Gerweck <sarah.a180@gmail.com>

Closes #1756 from sarahgerweck/folderSpaces and squashes the following commits:

732629d [Sarah Gerweck] Fix some bugs with spaces in directory name.
SPARK-2272 [MLlib] Feature scaling which standardizes the range of independent variables or features of data

Feature scaling is a method used to standardize the range of independent variables or features of data. In data processing, it is generally performed during the data preprocessing step.

In this work, a trait called `VectorTransformer` is defined for generic transformation on a vector. It contains one method to be implemented, `transform` which applies transformation on a vector.

There are two implementations of `VectorTransformer` now, and they all can be easily extended with PMML transformation support.

1) `StandardScaler` - Standardizes features by removing the mean and scaling to unit variance using column summary statistics on the samples in the training set.

2) `Normalizer` - Normalizes samples individually to unit L^n norm

Author: DB Tsai <dbtsai@alpinenow.com>

Closes #1207 from dbtsai/dbtsai-feature-scaling and squashes the following commits:

78c15d3 [DB Tsai] Alpine Data Labs
SPARK-2566. Update ShuffleWriteMetrics incrementally
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