[SPARK-1439, SPARK-1440] Generate unified Scaladoc across projects and Javadocs

I used the sbt-unidoc plugin (https://github.com/sbt/sbt-unidoc) to create a unified Scaladoc of our public packages, and generate Javadocs as well. One limitation is that I haven't found an easy way to exclude packages in the Javadoc; there is a SBT task that identifies Java sources to run javadoc on, but it's been very difficult to modify it from outside to change what is set in the unidoc package. Some SBT-savvy people should help with this. The Javadoc site also lacks package-level descriptions and things like that, so we may want to look into that. We may decide not to post these right now if it's too limited compared to the Scala one.

Example of the built doc site: http://people.csail.mit.edu/matei/spark-unified-docs/

Author: Matei Zaharia <matei@databricks.com>

This patch had conflicts when merged, resolved by
Committer: Patrick Wendell <pwendell@gmail.com>

Closes #457 from mateiz/better-docs and squashes the following commits:

a63d4a3 [Matei Zaharia] Skip Java/Scala API docs for Python package
5ea1f43 [Matei Zaharia] Fix links to Java classes in Java guide, fix some JS for scrolling to anchors on page load
f05abc0 [Matei Zaharia] Don't include java.lang package names
995e992 [Matei Zaharia] Skip internal packages and class names with $ in JavaDoc
a14a93c [Matei Zaharia] typo
76ce64d [Matei Zaharia] Add groups to Javadoc index page, and a first package-info.java
ed6f994 [Matei Zaharia] Generate JavaDoc as well, add titles, update doc site to use unified docs
acb993d [Matei Zaharia] Add Unidoc plugin for the projects we want Unidoced
[Fix #274] Document + fix annotation usages

... so that we don't follow an unspoken set of forbidden rules for adding **@AlphaComponent**, **@DeveloperApi**, and **@Experimental** annotations in the code.

In addition, this PR
(1) removes unnecessary `:: * ::` tags,
(2) adds missing `:: * ::` tags, and
(3) removes annotations for internal APIs.

Author: Andrew Or <andrewor14@gmail.com>

Closes #470 from andrewor14/annotations-fix and squashes the following commits:

92a7f42 [Andrew Or] Document + fix annotation usages
[SPARK-1459] Use local path (and not complete URL) when opening local lo...

...g file.

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #375 from vanzin/event-file and squashes the following commits:

f673029 [Marcelo Vanzin] [SPARK-1459] Use local path (and not complete URL) when opening local log file.
SPARK-1496: Have jarOfClass return Option[String]

A simple change, mostly had to change a bunch of example code.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #438 from pwendell/jar-of-class and squashes the following commits:

aa010ff [Patrick Wendell] SPARK-1496: Have jarOfClass return Option[String]
[HOTFIX] SPARK-1399: remove outdated comments

as the original PR was merged before this mistake is found....fix here,

Sorry about that @pwendell, @andrewor14, I will be more careful next time

Author: CodingCat <zhunansjtu@gmail.com>

Closes #474 from CodingCat/hotfix_1399 and squashes the following commits:

f3a8ba9 [CodingCat] move outdated comments
[SPARK-1560]: Updated Pyrolite Dependency to be Java 6 compatible

Changed the Pyrolite dependency to a build which targets Java 6.

Author: Ahir Reddy <ahirreddy@gmail.com>

Closes #479 from ahirreddy/java6-pyrolite and squashes the following commits:

8ea25d3 [Ahir Reddy] Updated maven build to use java 6 compatible pyrolite
dabc703 [Ahir Reddy] Updated Pyrolite dependency to be Java 6 compatible
fix bugs of dot in python

If there are no `transpose()` in `self.theta`, a

*ValueError: matrices are not aligned*

is occurring. The former test case just ignore this situation.

Author: Xusen Yin <yinxusen@gmail.com>

Closes #463 from yinxusen/python-naive-bayes and squashes the following commits:

fcbe3bc [Xusen Yin] fix bugs of dot in python
[SPARK-1281] Improve partitioning in ALS

ALS was using HashPartitioner and explicit uses of `%` together.  Further, the naked use of `%` meant that, if the number of partitions corresponded with the stride of arithmetic progressions appearing in user and product ids, users and products could be mapped into buckets in an unfair or unwise way.

This pull request:
1) Makes the Partitioner an instance variable of ALS.
2) Replaces the direct uses of `%` with calls to a Partitioner.
3) Defines an anonymous Partitioner that scrambles the bits of the object's hashCode before reducing to the number of present buckets.

This pull request does not make the partitioner user-configurable.

I'm not all that happy about the way I did (1).  It introduces an icky lifetime issue and dances around it by nulling something.  However, I don't know a better way to make the partitioner visible everywhere it needs to be visible.

Author: Tor Myklebust <tmyklebu@gmail.com>

Closes #407 from tmyklebu/master and squashes the following commits:

dcf583a [Tor Myklebust] Remove the partitioner member variable; instead, thread that needle everywhere it needs to go.
23d6f91 [Tor Myklebust] Stop making the partitioner configurable.
495784f [Tor Myklebust] Merge branch 'master' of https://github.com/apache/spark
674933a [Tor Myklebust] Fix style.
40edc23 [Tor Myklebust] Fix missing space.
f841345 [Tor Myklebust] Fix daft bug creating 'pairs', also for -> foreach.
5ec9e6c [Tor Myklebust] Clean a couple of things up using 'map'.
36a0f43 [Tor Myklebust] Make the partitioner private.
d872b09 [Tor Myklebust] Add negative id ALS test.
df27697 [Tor Myklebust] Support custom partitioners.  Currently we use the same partitioner for users and products.
c90b6d8 [Tor Myklebust] Scramble user and product ids before bucketing.
c774d7d [Tor Myklebust] Make the partitioner a member variable and use it instead of modding directly.
[SPARK-1506][MLLIB] Documentation improvements for MLlib 1.0

Preview: http://54.82.240.23:4000/mllib-guide.html

Table of contents:

* Basics
  * Data types
  * Summary statistics
* Classification and regression
  * linear support vector machine (SVM)
  * logistic regression
  * linear linear squares, Lasso, and ridge regression
  * decision tree
  * naive Bayes
* Collaborative Filtering
  * alternating least squares (ALS)
* Clustering
  * k-means
* Dimensionality reduction
  * singular value decomposition (SVD)
  * principal component analysis (PCA)
* Optimization
  * stochastic gradient descent
  * limited-memory BFGS (L-BFGS)

Author: Xiangrui Meng <meng@databricks.com>

Closes #422 from mengxr/mllib-doc and squashes the following commits:

944e3a9 [Xiangrui Meng] merge master
f9fda28 [Xiangrui Meng] minor
9474065 [Xiangrui Meng] add alpha to ALS examples
928e630 [Xiangrui Meng] initialization_mode -> initializationMode
5bbff49 [Xiangrui Meng] add imports to labeled point examples
c17440d [Xiangrui Meng] fix python nb example
28f40dc [Xiangrui Meng] remove localhost:4000
369a4d3 [Xiangrui Meng] Merge branch 'master' into mllib-doc
7dc95cc [Xiangrui Meng] update linear methods
053ad8a [Xiangrui Meng] add links to go back to the main page
abbbf7e [Xiangrui Meng] update ALS argument names
648283e [Xiangrui Meng] level down statistics
14e2287 [Xiangrui Meng] add sample libsvm data and use it in guide
8cd2441 [Xiangrui Meng] minor updates
186ab07 [Xiangrui Meng] update section names
6568d65 [Xiangrui Meng] update toc, level up lr and svm
162ee12 [Xiangrui Meng] rename section names
5c1e1b1 [Xiangrui Meng] minor
8aeaba1 [Xiangrui Meng] wrap long lines
6ce6a6f [Xiangrui Meng] add summary statistics to toc
5760045 [Xiangrui Meng] claim beta
cc604bf [Xiangrui Meng] remove classification and regression
92747b3 [Xiangrui Meng] make section titles consistent
e605dd6 [Xiangrui Meng] add LIBSVM loader
f639674 [Xiangrui Meng] add python section to migration guide
c82ffb4 [Xiangrui Meng] clean optimization
31660eb [Xiangrui Meng] update linear algebra and stat
0a40837 [Xiangrui Meng] first pass over linear methods
1fc8271 [Xiangrui Meng] update toc
906ed0a [Xiangrui Meng] add a python example to naive bayes
5f0a700 [Xiangrui Meng] update collaborative filtering
656d416 [Xiangrui Meng] update mllib-clustering
86e143a [Xiangrui Meng] remove data types section from main page
8d1a128 [Xiangrui Meng] move part of linear algebra to data types and add Java/Python examples
d1b5cbf [Xiangrui Meng] merge master
72e4804 [Xiangrui Meng] one pass over tree guide
64f8995 [Xiangrui Meng] move decision tree guide to a separate file
9fca001 [Xiangrui Meng] add first version of linear algebra guide
53c9552 [Xiangrui Meng] update dependencies
f316ec2 [Xiangrui Meng] add migration guide
f399f6c [Xiangrui Meng] move linear-algebra to dimensionality-reduction
182460f [Xiangrui Meng] add guide for naive Bayes
137fd1d [Xiangrui Meng] re-organize toc
a61e434 [Xiangrui Meng] update mllib's toc
[Fix #204] Eliminate delay between binding and log checking

**Bug**: In the existing history server, there is a `spark.history.updateInterval` seconds delay before application logs show up on the UI.

**Cause**: This is because the following events happen in this order: (1) The background thread that checks for logs starts, but realizes the server has not yet bound and so waits for N seconds, (2) server binds, (3) N seconds later the background thread finds that the server has finally bound to a port, and so finally checks for application logs.

**Fix**: This PR forces the log checking thread to start immediately after binding. It also documents two relevant environment variables that are currently missing.

Author: Andrew Or <andrewor14@gmail.com>

Closes #441 from andrewor14/history-server-fix and squashes the following commits:

b2eb46e [Andrew Or] Document SPARK_PUBLIC_DNS and SPARK_HISTORY_OPTS for the history server
e8d1fbc [Andrew Or] Eliminate delay between binding and checking for logs
Fix compilation on Hadoop 2.4.x.

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #483 from vanzin/yarn-2.4 and squashes the following commits:

0fc57d8 [Marcelo Vanzin] Fix compilation on Hadoop 2.4.x.
[SPARK-1570] Fix classloading in JavaSQLContext.applySchema

I think I hit a class loading issue when running JavaSparkSQL example using spark-submit in local mode.

Author: Kan Zhang <kzhang@apache.org>

Closes #484 from kanzhang/SPARK-1570 and squashes the following commits:

feaaeba [Kan Zhang] [SPARK-1570] Fix classloading in JavaSQLContext.applySchema
Assorted clean-up for Spark-on-YARN.

In particular when the HADOOP_CONF_DIR is not not specified.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #488 from pwendell/hadoop-cleanup and squashes the following commits:

fe95f13 [Patrick Wendell] Changes based on Andrew's feeback
18d09c1 [Patrick Wendell] Review comments from Andrew
17929cc [Patrick Wendell] Assorted clean-up for Spark-on-YARN.
[Spark-1538] Fix SparkUI incorrectly hiding persisted RDDs

**Bug**: After the following command `sc.parallelize(1 to 1000).persist.map(_ + 1).count()` is run, the the persisted RDD is missing from the storage tab of the SparkUI.

**Cause**: The command creates two RDDs in one stage, a `ParallelCollectionRDD` and a `MappedRDD`. However, the existing StageInfo only keeps the RDDInfo of the last RDD associated with the stage (`MappedRDD`), and so all RDD information regarding the first RDD (`ParallelCollectionRDD`) is discarded. In this case, we persist the first RDD,  but the StorageTab doesn't know about this RDD because it is not encoded in the StageInfo.

**Fix**: Record information of all RDDs in StageInfo, instead of just the last RDD (i.e. `stage.rdd`). Since stage boundaries are marked by shuffle dependencies, the solution is to traverse the last RDD's dependency tree, visiting only ancestor RDDs related through a sequence of narrow dependencies.

---

This PR also moves RDDInfo to its own file, includes a few style fixes, and adds a unit test for constructing StageInfos.

Author: Andrew Or <andrewor14@gmail.com>

Closes #469 from andrewor14/storage-ui-fix and squashes the following commits:

07fc7f0 [Andrew Or] Add back comment that was accidentally removed (minor)
5d799fe [Andrew Or] Add comment to justify testing of getNarrowAncestors with cycles
9d0e2b8 [Andrew Or] Hide details of getNarrowAncestors from outsiders
d2bac8a [Andrew Or] Deal with cycles in RDD dependency graph + add extensive tests
2acb177 [Andrew Or] Move getNarrowAncestors to RDD.scala
bfe83f0 [Andrew Or] Backtrace RDD dependency tree to find all RDDs that belong to a Stage
[streaming][SPARK-1578] Removed requirement for TTL in StreamingContext.

Since shuffles and RDDs that are out of context are automatically cleaned by Spark core (using ContextCleaner) there is no need for setting the cleaner TTL while creating a StreamingContext.

Author: Tathagata Das <tathagata.das1565@gmail.com>

Closes #491 from tdas/ttl-fix and squashes the following commits:

cf01dc7 [Tathagata Das] Removed requirement for TTL in StreamingContext.
[FIX: SPARK-1376] use --arg instead of --args in SparkSubmit to avoid warning messages

Even if users use `--arg`, `SparkSubmit` still uses `--args` for child args internally, which triggers a warning message that may confuse users:

~~~
--args is deprecated. Use --arg instead.
~~~

@sryza Does it look good to you?

Author: Xiangrui Meng <meng@databricks.com>

Closes #485 from mengxr/submit-arg and squashes the following commits:

5e1b9fe [Xiangrui Meng] update test
cebbeb7 [Xiangrui Meng] use --arg instead of --args in SparkSubmit to avoid warning messages
SPARK-1562 Fix visibility / annotation of Spark SQL APIs

Author: Michael Armbrust <michael@databricks.com>

Closes #489 from marmbrus/sqlDocFixes and squashes the following commits:

acee4f3 [Michael Armbrust] Fix visibility / annotation of Spark SQL APIs
SPARK-1494 Don't initialize classes loaded by MIMA excludes.

[WIP]  Just seeing how Jenkins likes this...

Author: Michael Armbrust <michael@databricks.com>

Closes #494 from marmbrus/mima and squashes the following commits:

6eec616 [Michael Armbrust] Force hive tests to run.
acaf682 [Michael Armbrust] Don't initialize loaded classes.
[SQL] SPARK-1571 Mistake in java example code

Author: Michael Armbrust <michael@databricks.com>

Closes #496 from marmbrus/javaBeanBug and squashes the following commits:

644fedd [Michael Armbrust] Bean methods must be public.
SPARK-1119 and other build improvements

1. Makes assembly and examples jar naming consistent in maven/sbt.
2. Updates make-distribution.sh to use Maven and fixes some bugs.
3. Updates the create-release script to call make-distribution script.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #502 from pwendell/make-distribution and squashes the following commits:

1a97f0d [Patrick Wendell] SPARK-1119 and other build improvements