[SPARK-2534] Avoid pulling in the entire RDD in various operators

This should go into both master and branch-1.0.

Author: Reynold Xin <rxin@apache.org>

Closes #1450 from rxin/agg-closure and squashes the following commits:

e40f363 [Reynold Xin] Mima check excludes.
9186364 [Reynold Xin] Define the return type more explicitly.
38e348b [Reynold Xin] Fixed the cases in RDD.scala.
ea6b34d [Reynold Xin] Blah
89b9c43 [Reynold Xin] Fix other instances of accidentally pulling in extra stuff in closures.
73b2783 [Reynold Xin] [SPARK-2534] Avoid pulling in the entire RDD in groupByKey.
SPARK-1478.2 Fix incorrect NioServerSocketChannelFactory constructor call

The line break inadvertently means this was interpreted as a call to the no-arg constructor. This doesn't exist in older Netty even. (Also fixed a val name typo.)

Author: Sean Owen <srowen@gmail.com>

Closes #1466 from srowen/SPARK-1478.2 and squashes the following commits:

59c3501 [Sean Owen] Line break caused Scala to interpret NioServerSocketChannelFactory constructor as the no-arg version, which is not even present in some versions of Netty
SPARK-1215 [MLLIB]: Clustering: Index out of bounds error (2)

Added check to LocalKMeans.scala: kMeansPlusPlus initialization to handle case with fewer distinct data points than clusters k.  Added two related unit tests to KMeansSuite.  (Re-submitting PR after tangling commits in PR 1407 https://github.com/apache/spark/pull/1407 )

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

Closes #1468 from jkbradley/kmeans-fix and squashes the following commits:

4e9bd1e [Joseph K. Bradley] Updated PR per comments from mengxr
6c7a2ec [Joseph K. Bradley] Added check to LocalKMeans.scala: kMeansPlusPlus initialization to handle case with fewer distinct data points than clusters k.  Added two related unit tests to KMeansSuite.
[SPARK-2299] Consolidate various stageIdTo* hash maps in JobProgressListener

This should reduce memory usage for the web ui as well as slightly increase its speed in draining the UI event queue.

@andrewor14

Author: Reynold Xin <rxin@apache.org>

Closes #1262 from rxin/ui-consolidate-hashtables and squashes the following commits:

1ac3f97 [Reynold Xin] Oops. Properly handle description.
f5736ad [Reynold Xin] Code review comments.
b8828dc [Reynold Xin] Merge branch 'master' into ui-consolidate-hashtables
7a7b6c4 [Reynold Xin] Revert css change.
f959bb8 [Reynold Xin] [SPARK-2299] Consolidate various stageIdTo* hash maps in JobProgressListener to speed it up.
63256f5 [Reynold Xin] [SPARK-2320] Reduce <pre> block font size.
[SPARK-2411] Add a history-not-found page to standalone Master

**Problem.** Right now, if you click on an application after it has finished, it simply refreshes the page if there are no event logs for the application. This is not super intuitive especially because event logging is not enabled by default. We should direct the user to enable this if they attempt to view a SparkUI after the fact without event logs.

**Fix.** The new page conveys different messages in each of the following scenarios:
(1) Application did not enable event logging,
(2) Event logs are not found in the specified directory, and
(3) Exception is thrown while replaying the logs

Here are screenshots of what the page looks like in each of the above scenarios:

(1)
<img src="https://issues.apache.org/jira/secure/attachment/12656204/Event%20logging%20not%20enabled.png" width="75%">

(2)
<img src="https://issues.apache.org/jira/secure/attachment/12656203/Application%20history%20not%20found.png">

(3)
<img src="https://issues.apache.org/jira/secure/attachment/12656202/Application%20history%20load%20error.png" width="95%">

Author: Andrew Or <andrewor14@gmail.com>

Closes #1336 from andrewor14/master-link and squashes the following commits:

2f06206 [Andrew Or] Merge branch 'master' of github.com:apache/spark into master-link
97cddc0 [Andrew Or] Add different severity levels
832b687 [Andrew Or] Mention spark.eventLog.dir in error message
51980c3 [Andrew Or] Merge branch 'master' of github.com:apache/spark into master-link
ded208c [Andrew Or] Merge branch 'master' of github.com:apache/spark into master-link
89d6405 [Andrew Or] Reword message
e7df7ed [Andrew Or] Add a history not found page to standalone Master
[SPARK-2570] [SQL] Fix the bug of ClassCastException

Exception thrown when running the example of HiveFromSpark.
Exception in thread "main" java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.Integer
	at scala.runtime.BoxesRunTime.unboxToInt(BoxesRunTime.java:106)
	at org.apache.spark.sql.catalyst.expressions.GenericRow.getInt(Row.scala:145)
	at org.apache.spark.examples.sql.hive.HiveFromSpark$.main(HiveFromSpark.scala:45)
	at org.apache.spark.examples.sql.hive.HiveFromSpark.main(HiveFromSpark.scala)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.spark.deploy.SparkSubmit$.launch(SparkSubmit.scala:303)
	at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:55)
	at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)

Author: Cheng Hao <hao.cheng@intel.com>

Closes #1475 from chenghao-intel/hive_from_spark and squashes the following commits:

d4c0500 [Cheng Hao] Fix the bug of ClassCastException
SPARK-2553. CoGroupedRDD unnecessarily allocates a Tuple2 per dependency...

... per key

My humble opinion is that avoiding allocations in this performance-critical section is worth the extra code.

Author: Sandy Ryza <sandy@cloudera.com>

Closes #1461 from sryza/sandy-spark-2553 and squashes the following commits:

7eaf7f2 [Sandy Ryza] SPARK-2553. CoGroupedRDD unnecessarily allocates a Tuple2 per dependency per key
SPARK-2553. Fix compile error

Author: Sandy Ryza <sandy@cloudera.com>

Closes #1479 from sryza/sandy-spark-2553 and squashes the following commits:

2cb5ed8 [Sandy Ryza] SPARK-2553. Fix compile error