HOTFIX: Don't build Javadoc in Maven when creating releases.

Because we've added java package descriptions in some packages that don't
have any Java files, running the Javadoc target hits this issue:

http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4492654

To fix this I've simply removed the javadoc target when publishing
releases.
SPARK-1846 Ignore logs directory in RAT checks

https://issues.apache.org/jira/browse/SPARK-1846

Author: Andrew Ash <andrew@andrewash.com>

Closes #793 from ash211/SPARK-1846 and squashes the following commits:

3f50db5 [Andrew Ash] SPARK-1846 Ignore logs directory in RAT checks
[SPARK-1845] [SQL] Use AllScalaRegistrar for SparkSqlSerializer to register serializers of ...

...Scala collections.

When I execute `orderBy` or `limit` for `SchemaRDD` including `ArrayType` or `MapType`, `SparkSqlSerializer` throws the following exception:

```
com.esotericsoftware.kryo.KryoException: Class cannot be created (missing no-arg constructor): scala.collection.immutable.$colon$colon
```

or

```
com.esotericsoftware.kryo.KryoException: Class cannot be created (missing no-arg constructor): scala.collection.immutable.Vector
```

or

```
com.esotericsoftware.kryo.KryoException: Class cannot be created (missing no-arg constructor): scala.collection.immutable.HashMap$HashTrieMap
```

and so on.

This is because registrations of serializers for each concrete collections are missing in `SparkSqlSerializer`.
I believe it should use `AllScalaRegistrar`.
`AllScalaRegistrar` covers a lot of serializers for concrete classes of `Seq`, `Map` for `ArrayType`, `MapType`.

Author: Takuya UESHIN <ueshin@happy-camper.st>

Closes #790 from ueshin/issues/SPARK-1845 and squashes the following commits:

d1ed992 [Takuya UESHIN] Use AllScalaRegistrar for SparkSqlSerializer to register serializers of Scala collections.
[SPARK-1819] [SQL] Fix GetField.nullable.

`GetField.nullable` should be `true` not only when `field.nullable` is `true` but also when `child.nullable` is `true`.

Author: Takuya UESHIN <ueshin@happy-camper.st>

Closes #757 from ueshin/issues/SPARK-1819 and squashes the following commits:

8781a11 [Takuya UESHIN] Modify a test to use named parameters.
5bfc77d [Takuya UESHIN] Fix GetField.nullable.
[SPARK-1741][MLLIB] add predict(JavaRDD) to RegressionModel, ClassificationModel, and KMeans

`model.predict` returns a RDD of Scala primitive type (Int/Double), which is recognized as Object in Java. Adding predict(JavaRDD) could make life easier for Java users.

Added tests for KMeans, LinearRegression, and NaiveBayes.

Will update examples after https://github.com/apache/spark/pull/653 gets merged.

cc: @srowen

Author: Xiangrui Meng <meng@databricks.com>

Closes #670 from mengxr/predict-javardd and squashes the following commits:

b77ccd8 [Xiangrui Meng] Merge branch 'master' into predict-javardd
43caac9 [Xiangrui Meng] add predict(JavaRDD) to RegressionModel, ClassificationModel, and KMeans
Merge branch 'master' of github.com:apache/spark into pyspark-submit