[SPARK-2384] Add tooltips to UI.

This patch adds tooltips to clarify some points of confusion in the UI.  When users mouse over some of the table headers (shuffle read, write, and input size) as well as over the "scheduler delay" metric shown for each stage, a black tool tip (see image below) pops up describing the metric in more detail.  After the tooltip mechanism is added by this commit, I imagine others may want to add more tooltips for other things in the UI, but I think this is a good starting point.

![tooltip](https://cloud.githubusercontent.com/assets/1108612/3491905/994e179e-059f-11e4-92f2-c6c12d248d81.jpg)

This looks scary-big but much of it is adding the bootstrap tool tip JavaScript.

Also I have no idea what to put for the license in tooltip (I left it the same -- the Twitter apache header) or for JQuery (left it as nothing) -- @mateiz what's the right thing here?

cc @pwendell @andrewor14 @rxin

Author: Kay Ousterhout <kayousterhout@gmail.com>

Closes #1314 from kayousterhout/tooltips and squashes the following commits:

19981b5 [Kay Ousterhout] Exclude non-licensed javascript files from style check
d9ab5a9 [Kay Ousterhout] Response to Andrew's review
7752449 [Kay Ousterhout] [SPARK-2384] Add tooltips to UI.
[STREAMING] SPARK-2343: Fix QueueInputDStream with oneAtATime false

Fix QueueInputDStream which was not removing dequeued items when used with the oneAtATime flag disabled.

Author: Manuel Laflamme <manuel.laflamme@gmail.com>

Closes #1285 from mlaflamm/spark-2343 and squashes the following commits:

61c9e38 [Manuel Laflamme] Unit tests for queue input stream
c51d029 [Manuel Laflamme] Fix QueueInputDStream with oneAtATime false
[SPARK-2417][MLlib] Fix DecisionTree tests

Fixes test failures introduced by https://github.com/apache/spark/pull/1316.

For both the regression and classification cases,
val stats is the InformationGainStats for the best tree split.
stats.predict is the predicted value for the data, before the split is made.
Since 600 of the 1,000 values generated by DecisionTreeSuite.generateCategoricalDataPoints() are 1.0 and the rest 0.0, the regression tree and classification tree both correctly predict a value of 0.6 for this data now, and the assertions have been changed to reflect that.

Author: johnnywalleye <jsondag@gmail.com>

Closes #1343 from johnnywalleye/decision-tree-tests and squashes the following commits:

ef80603 [johnnywalleye] [SPARK-2417][MLlib] Fix DecisionTree tests
SPARK-1782: svd for sparse matrix using ARPACK

copy ARPACK dsaupd/dseupd code from latest breeze
change RowMatrix to use sparse SVD
change tests for sparse SVD

All tests passed. I will run it against some large matrices.

Author: Li Pu <lpu@twitter.com>
Author: Xiangrui Meng <meng@databricks.com>
Author: Li Pu <li.pu@outlook.com>

Closes #964 from vrilleup/master and squashes the following commits:

7312ec1 [Li Pu] very minor comment fix
4c618e9 [Li Pu] Merge pull request #1 from mengxr/vrilleup-master
a461082 [Xiangrui Meng] make superscript show up correctly in doc
861ec48 [Xiangrui Meng] simplify axpy
62969fa [Xiangrui Meng] use BDV directly in symmetricEigs change the computation mode to local-svd, local-eigs, and dist-eigs update tests and docs
c273771 [Li Pu] automatically determine SVD compute mode and parameters
7148426 [Li Pu] improve RowMatrix multiply
5543cce [Li Pu] improve svd api
819824b [Li Pu] add flag for dense svd or sparse svd
eb15100 [Li Pu] fix binary compatibility
4c7aec3 [Li Pu] improve comments
e7850ed [Li Pu] use aggregate and axpy
827411b [Li Pu] fix EOF new line
9c80515 [Li Pu] use non-sparse implementation when k = n
fe983b0 [Li Pu] improve scala style
96d2ecb [Li Pu] improve eigenvalue sorting
e1db950 [Li Pu] SPARK-1782: svd for sparse matrix using ARPACK
SPARK-2416: Allow richer reporting of unit test results

The built-in Jenkins integration is pretty bad. It's very confusing to users whether tests have passed or failed and we can't easily customize the message.

With some small scripting around the Github API we can do much better than this.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #1340 from pwendell/better-qa-messages and squashes the following commits:

fd6077d [Patrick Wendell] Better automation for unit tests.
Revert "[HOTFIX] Synchronize on SQLContext.settings in tests."

This reverts commit d4c30cd9918e18dde2a52909e36eaef6eb5996ab.
HOTFIX: Remove persistently failing test in master.

Apparently this functionality is going to be removed soon anywyas.
Clean up SparkKMeans example's code

remove unused code

Author: Raymond Liu <raymond.liu@intel.com>

Closes #1352 from colorant/kmeans and squashes the following commits:

ddcd1dd [Raymond Liu] Clean up SparkKMeans example's code
SPARK-2115: Stage kill link is too close to stage details link

Moved (kill) link to the right side. Add confirmation dialog when (kill) link is clicked.

Author: Masayoshi TSUZUKI <tsudukim@oss.nttdata.co.jp>

Closes #1350 from tsudukim/feature/SPARK-2115 and squashes the following commits:

e2263b0 [Masayoshi TSUZUKI] Moved (kill) link to the right side. Add confirmation dialog when (kill) link is clicked.
[SPARK-1776] Have Spark's SBT build read dependencies from Maven.

Patch introduces the new way of working also retaining the existing ways of doing things.

For example build instruction for yarn in maven is
`mvn -Pyarn -PHadoop2.2 clean package -DskipTests`
in sbt it can become
`MAVEN_PROFILES="yarn, hadoop-2.2" sbt/sbt clean assembly`
Also supports
`sbt/sbt -Pyarn -Phadoop-2.2 -Dhadoop.version=2.2.0 clean assembly`

Author: Prashant Sharma <prashant.s@imaginea.com>
Author: Patrick Wendell <pwendell@gmail.com>

Closes #772 from ScrapCodes/sbt-maven and squashes the following commits:

a8ac951 [Prashant Sharma] Updated sbt version.
62b09bb [Prashant Sharma] Improvements.
fa6221d [Prashant Sharma] Excluding sql from mima
4b8875e [Prashant Sharma] Sbt assembly no longer builds tools by default.
72651ca [Prashant Sharma] Addresses code reivew comments.
acab73d [Prashant Sharma] Revert "Small fix to run-examples script."
ac4312c [Prashant Sharma] Revert "minor fix"
6af91ac [Prashant Sharma] Ported oldDeps back. + fixes issues with prev commit.
65cf06c [Prashant Sharma] Servelet API jars mess up with the other servlet jars on the class path.
446768e [Prashant Sharma] minor fix
89b9777 [Prashant Sharma] Merge conflicts
d0a02f2 [Prashant Sharma] Bumped up pom versions, Since the build now depends on pom it is better updated there. + general cleanups.
dccc8ac [Prashant Sharma] updated mima to check against 1.0
a49c61b [Prashant Sharma] Fix for tools jar
a2f5ae1 [Prashant Sharma] Fixes a bug in dependencies.
cf88758 [Prashant Sharma] cleanup
9439ea3 [Prashant Sharma] Small fix to run-examples script.
96cea1f [Prashant Sharma] SPARK-1776 Have Spark's SBT build read dependencies from Maven.
36efa62 [Patrick Wendell] Set project name in pom files and added eclipse/intellij plugins.
4973dbd [Patrick Wendell] Example build using pom reader.
HOTFIX: Minor doc update for sbt change
name ec2 instances and security groups consistently

Security groups created by `spark-ec2` do not prepend “spark-“ to the
name.

Since naming the instances themselves is new to `spark-ec2`, it’s better
to change that pattern to match the existing naming pattern for the
security groups, rather than the other way around.

Author: Nicholas Chammas <nicholas.chammas@gmail.com>
Author: nchammas <nicholas.chammas@gmail.com>

Closes #1344 from nchammas/master and squashes the following commits:

f7e4581 [Nicholas Chammas] unrelated pep8 fix
a36eed0 [Nicholas Chammas] name ec2 instances and security groups consistently
de7292a [nchammas] Merge pull request #4 from apache/master
2e4fe00 [nchammas] Merge pull request #3 from apache/master
89fde08 [nchammas] Merge pull request #2 from apache/master
69f6e22 [Nicholas Chammas] PEP8 fixes
2627247 [Nicholas Chammas] broke up lines before they hit 100 chars
6544b7e [Nicholas Chammas] [SPARK-2065] give launched instances names
69da6cf [nchammas] Merge pull request #1 from apache/master
[SPARK-1478].3: Upgrade FlumeInputDStream's FlumeReceiver to support FLUME-1915

This is a modified version of this PR https://github.com/apache/spark/pull/1168 done by @tmalaska
Adds MIMA binary check exclusions.

Author: tmalaska <ted.malaska@cloudera.com>
Author: Tathagata Das <tathagata.das1565@gmail.com>

Closes #1347 from tdas/FLUME-1915 and squashes the following commits:

96065df [Tathagata Das] Added Mima exclusion for FlumeReceiver.
41d5338 [tmalaska] Address line 57 that was too long
12617e5 [tmalaska] SPARK-1478: Upgrade FlumeInputDStream's Flume...
[SPARK-1341] [Streaming] Throttle BlockGenerator to limit rate of data consumption.

Author: Issac Buenrostro <buenrostro@ooyala.com>

Closes #945 from ibuenros/SPARK-1341-throttle and squashes the following commits:

5514916 [Issac Buenrostro] Formatting changes, added documentation for streaming throttling, stricter unit tests for throttling.
62f395f [Issac Buenrostro] Add comments and license to streaming RateLimiter.scala
7066438 [Issac Buenrostro] Moved throttle code to RateLimiter class, smoother pushing when throttling active
ccafe09 [Issac Buenrostro] Throttle BlockGenerator to limit rate of data consumption.
SPARK-2427: Fix Scala examples that use the wrong command line arguments index

The Scala examples HBaseTest and HdfsTest don't use the correct indexes for the command line arguments. This due to to the fix of JIRA 1565, where these examples were not correctly adapted to the new usage of the submit script.

Author: Artjom-Metro <Artjom-Metro@users.noreply.github.com>
Author: Artjom-Metro <artjom31415@googlemail.com>

Closes #1353 from Artjom-Metro/fix_examples and squashes the following commits:

6111801 [Artjom-Metro] Reduce the default number of iterations
cfaa73c [Artjom-Metro] Fix some examples that use the wrong index to access the command line arguments