SPARK-1352: Improve robustness of spark-submit script

1. Better error messages when required arguments are missing.
2. Support for unit testing cases where presented arguments are invalid.
3. Bug fix: Only use environment varaibles when they are set (otherwise will cause NPE).
4. A verbose mode to aid debugging.
5. Visibility of several variables is set to private.
6. Deprecation warning for existing scripts.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #271 from pwendell/spark-submit and squashes the following commits:

9146def [Patrick Wendell] SPARK-1352: Improve robustness of spark-submit script
[SQL] Rewrite join implementation to allow streaming of one relation.

Before we were materializing everything in memory.  This also uses the projection interface so will be easier to plug in code gen (its ported from that branch).

@rxin @liancheng

Author: Michael Armbrust <michael@databricks.com>

Closes #250 from marmbrus/hashJoin and squashes the following commits:

1ad873e [Michael Armbrust] Change hasNext logic back to the correct version.
8e6f2a2 [Michael Armbrust] Review comments.
1e9fb63 [Michael Armbrust] style
bc0cb84 [Michael Armbrust] Rewrite join implementation to allow streaming of one relation.
SPARK-1365 [HOTFIX] Fix RateLimitedOutputStream test

This test needs to be fixed. It currently depends on Thread.sleep() having exact-timing
semantics, which is not a valid assumption.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #277 from pwendell/rate-limited-stream and squashes the following commits:

6c0ff81 [Patrick Wendell] SPARK-1365: Fix RateLimitedOutputStream test
SPARK-1376. In the yarn-cluster submitter, rename "args" option to "arg"

Author: Sandy Ryza <sandy@cloudera.com>

Closes #279 from sryza/sandy-spark-1376 and squashes the following commits:

d8aebfa [Sandy Ryza] SPARK-1376. In the yarn-cluster submitter, rename "args" option to "arg"
[SPARK-1377] Upgrade Jetty to 8.1.14v20131031

Previous version was 7.6.8v20121106. The only difference between Jetty 7 and Jetty 8 is that the former uses Servlet API 2.5, while the latter uses Servlet API 3.0.

Author: Andrew Or <andrewor14@gmail.com>

Closes #280 from andrewor14/jetty-upgrade and squashes the following commits:

dd57104 [Andrew Or] Merge github.com:apache/spark into jetty-upgrade
e75fa85 [Andrew Or] Upgrade Jetty to 8.1.14v20131031
[Hot Fix #42] Persisted RDD disappears on storage page if re-used

If a previously persisted RDD is re-used, its information disappears from the Storage page.

This is because the tasks associated with re-using the RDD do not report the RDD's blocks as updated (which is correct). On stage submit, however, we overwrite any existing information regarding that RDD with a fresh one, whether or not the information for the RDD already exists.

Author: Andrew Or <andrewor14@gmail.com>

Closes #281 from andrewor14/ui-storage-fix and squashes the following commits:

408585a [Andrew Or] Fix storage UI bug
[SQL] SPARK-1372 Support for caching and uncaching tables in a SQLContext.

This doesn't yet support different databases in Hive (though you can probably workaround this by calling `USE <dbname>`).  However, given the time constraints for 1.0 I think its probably worth including this now and extending the functionality in the next release.

Author: Michael Armbrust <michael@databricks.com>

Closes #282 from marmbrus/cacheTables and squashes the following commits:

83785db [Michael Armbrust] Support for caching and uncaching tables in a SQLContext.
[SPARK-1342] Scala 2.10.4

Just a Scala version increment

Author: Mark Hamstra <markhamstra@gmail.com>

Closes #259 from markhamstra/scala-2.10.4 and squashes the following commits:

fbec547 [Mark Hamstra] [SPARK-1342] Bumped Scala version to 2.10.4
[Spark-1134] only call ipython if no arguments are given; remove IPYTHONOPTS from call

see comments on Pull Request https://github.com/apache/spark/pull/38
(i couldn't figure out how to modify an existing pull request, so I'm hoping I can withdraw that one and replace it with this one.)

Author: Diana Carroll <dcarroll@cloudera.com>

Closes #227 from dianacarroll/spark-1134 and squashes the following commits:

ffe47f2 [Diana Carroll] [spark-1134] remove ipythonopts from ipython command
b673bf7 [Diana Carroll] Merge branch 'master' of github.com:apache/spark
0309cf9 [Diana Carroll] SPARK-1134 bug with ipython prevents non-interactive use with spark; only call ipython if no command line arguments were supplied
Revert "[Spark-1134] only call ipython if no arguments are given; remove IPYTHONOPTS from call"

This reverts commit afb5ea62786e3ca055e247176def3e7ecf0d2c9d.
MLI-1 Decision Trees

Joint work with @hirakendu, @etrain, @atalwalkar and @harsha2010.

Key features:
+ Supports binary classification and regression
+ Supports gini, entropy and variance for information gain calculation
+ Supports both continuous and categorical features

The algorithm has gone through several development iterations over the last few months leading to a highly optimized implementation. Optimizations include:

1. Level-wise training to reduce passes over the entire dataset.
2. Bin-wise split calculation to reduce computation overhead.
3. Aggregation over partitions before combining to reduce communication overhead.

Author: Manish Amde <manish9ue@gmail.com>
Author: manishamde <manish9ue@gmail.com>
Author: Xiangrui Meng <meng@databricks.com>

Closes #79 from manishamde/tree and squashes the following commits:

1e8c704 [Manish Amde] remove numBins field in the Strategy class
7d54b4f [manishamde] Merge pull request #4 from mengxr/dtree
f536ae9 [Xiangrui Meng] another pass on code style
e1dd86f [Manish Amde] implementing code style suggestions
62dc723 [Manish Amde] updating javadoc and converting helper methods to package private to allow unit testing
201702f [Manish Amde] making some more methods private
f963ef5 [Manish Amde] making methods private
c487e6a [manishamde] Merge pull request #1 from mengxr/dtree
24500c5 [Xiangrui Meng] minor style updates
4576b64 [Manish Amde] documentation and for to while loop conversion
ff363a7 [Manish Amde] binary search for bins and while loop for categorical feature bins
632818f [Manish Amde] removing threshold for classification predict method
2116360 [Manish Amde] removing dummy bin calculation for categorical variables
6068356 [Manish Amde] ensuring num bins is always greater than max number of categories
62c2562 [Manish Amde] fixing comment indentation
ad1fc21 [Manish Amde] incorporated mengxr's code style suggestions
d1ef4f6 [Manish Amde] more documentation
794ff4d [Manish Amde] minor improvements to docs and style
eb8fcbe [Manish Amde] minor code style updates
cd2c2b4 [Manish Amde] fixing code style based on feedback
63e786b [Manish Amde] added multiple train methods for java compatability
d3023b3 [Manish Amde] adding more docs for nested methods
84f85d6 [Manish Amde] code documentation
9372779 [Manish Amde] code style: max line lenght <= 100
dd0c0d7 [Manish Amde] minor: some docs
0dd7659 [manishamde] basic doc
5841c28 [Manish Amde] unit tests for categorical features
f067d68 [Manish Amde] minor cleanup
c0e522b [Manish Amde] updated predict and split threshold logic
b09dc98 [Manish Amde] minor refactoring
6b7de78 [Manish Amde] minor refactoring and tests
d504eb1 [Manish Amde] more tests for categorical features
dbb7ac1 [Manish Amde] categorical feature support
6df35b9 [Manish Amde] regression predict logic
53108ed [Manish Amde] fixing index for highest bin
e23c2e5 [Manish Amde] added regression support
c8f6d60 [Manish Amde] adding enum for feature type
b0e3e76 [Manish Amde] adding enum for feature type
154aa77 [Manish Amde] enums for configurations
733d6dd [Manish Amde] fixed tests
02c595c [Manish Amde] added command line parsing
98ec8d5 [Manish Amde] tree building and prediction logic
b0eb866 [Manish Amde] added logic to handle leaf nodes
80e8c66 [Manish Amde] working version of multi-level split calculation
4798aae [Manish Amde] added gain stats class
dad0afc [Manish Amde] decison stump functionality working
03f534c [Manish Amde] some more tests
0012a77 [Manish Amde] basic stump working
8bca1e2 [Manish Amde] additional code for creating intermediate RDD
92cedce [Manish Amde] basic building blocks for intermediate RDD calculation. untested.
cd53eae [Manish Amde] skeletal framework
Remove * from test case golden filename.

@rxin mentioned this might cause issues on windows machines.

Author: Michael Armbrust <michael@databricks.com>

Closes #297 from marmbrus/noStars and squashes the following commits:

263122a [Michael Armbrust] Remove * from test case golden filename.
Renamed stageIdToActiveJob to jobIdToActiveJob.

This data structure was misused and, as a result, later renamed to an incorrect name.

This data structure seems to have gotten into this tangled state as a result of @henrydavidge using the stageID instead of the job Id to index into it and later @andrewor14 renaming the data structure to reflect this misunderstanding.

This patch renames it and removes an incorrect indexing into it.  The incorrect indexing into it meant that the code added by @henrydavidge to warn when a task size is too large (added here https://github.com/apache/spark/commit/57579934f0454f258615c10e69ac2adafc5b9835) was not always executed; this commit fixes that.

Author: Kay Ousterhout <kayousterhout@gmail.com>

Closes #301 from kayousterhout/fixCancellation and squashes the following commits:

bd3d3a4 [Kay Ousterhout] Renamed stageIdToActiveJob to jobIdToActiveJob.
[SPARK-1385] Use existing code for JSON de/serialization of BlockId

`BlockId.scala` offers a way to reconstruct a BlockId from a string through regex matching. `util/JsonProtocol.scala` duplicates this functionality by explicitly matching on the BlockId type.
With this PR, the de/serialization of BlockIds will go through the first (older) code path.

(Most of the line changes in this PR involve changing `==` to `===` in `JsonProtocolSuite.scala`)

Author: Andrew Or <andrewor14@gmail.com>

Closes #289 from andrewor14/blockid-json and squashes the following commits:

409d226 [Andrew Or] Simplify JSON de/serialization for BlockId