[SPARK-1870] Make spark-submit --jars work in yarn-cluster mode.

Sent secondary jars to distributed cache of all containers and add the cached jars to classpath before executors start. Tested on a YARN cluster (CDH-5.0).

`spark-submit --jars` also works in standalone server and `yarn-client`. Thanks for @andrewor14 for testing!

I removed "Doesn't work for drivers in standalone mode with "cluster" deploy mode." from `spark-submit`'s help message, though we haven't tested mesos yet.

CC: @dbtsai @sryza

Author: Xiangrui Meng <meng@databricks.com>

Closes #848 from mengxr/yarn-classpath and squashes the following commits:

23e7df4 [Xiangrui Meng] rename spark.jar to __spark__.jar and app.jar to __app__.jar to avoid confliction apped $CWD/ and $CWD/* to the classpath remove unused methods
a40f6ed [Xiangrui Meng] standalone -> cluster
65e04ad [Xiangrui Meng] update spark-submit help message and add a comment for yarn-client
11e5354 [Xiangrui Meng] minor changes
3e7e1c4 [Xiangrui Meng] use sparkConf instead of hadoop conf
dc3c825 [Xiangrui Meng] add secondary jars to classpath in yarn

(cherry picked from commit dba314029b4c9d72d7e48a2093b39edd01931f57)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>
Fix UISuite unit test that fails under Jenkins contention

Due to perhaps zombie processes on Jenkins, it seems that at least 10
Spark ports are in use. It also doesn't matter that the port increases
when used, it could in fact go down -- the only part that matters is
that it selects a different port rather than failing to bind.
Changed test to match this.

Thanks to @andrewor14 for helping diagnose this.

Author: Aaron Davidson <aaron@databricks.com>

Closes #857 from aarondav/tiny and squashes the following commits:

c199ec8 [Aaron Davidson] Fix UISuite unit test that fails under Jenkins contention

(cherry picked from commit f9f5fd5f4e81828a3e0c391892e0f28751568843)
Signed-off-by: Reynold Xin <rxin@apache.org>
[SPARK-1897] Respect spark.jars (and --jars) in spark-shell

Spark shell currently overwrites `spark.jars` with `ADD_JARS`. In all modes except yarn-cluster, this means the `--jar` flag passed to `bin/spark-shell` is also discarded. However, in the [docs](http://people.apache.org/~pwendell/spark-1.0.0-rc7-docs/scala-programming-guide.html#initializing-spark), we explicitly tell the users to add the jars this way.

Author: Andrew Or <andrewor14@gmail.com>

Closes #849 from andrewor14/shell-jars and squashes the following commits:

928a7e6 [Andrew Or] ',' -> "," (minor)
afc357c [Andrew Or] Handle spark.jars == "" in SparkILoop, not SparkSubmit
c6da113 [Andrew Or] Do not set spark.jars to ""
d8549f7 [Andrew Or] Respect spark.jars and --jars in spark-shell

(cherry picked from commit 8edbee7d1b4afc192d97ba192a5526affc464205)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>
[SPARK-1896] Respect spark.master (and --master) before MASTER in spark-shell

The hierarchy for configuring the Spark master in the shell is as follows:
```
MASTER > --master > spark.master (spark-defaults.conf)
```
This is inconsistent with the way we run normal applications, which is:
```
--master > spark.master (spark-defaults.conf) > MASTER
```

I was trying to run a shell locally on a standalone cluster launched through the ec2 scripts, which automatically set `MASTER` in spark-env.sh. It was surprising to me that `--master` didn't take effect, considering that this is the way we tell users to set their masters [here](http://people.apache.org/~pwendell/spark-1.0.0-rc7-docs/scala-programming-guide.html#initializing-spark).

Author: Andrew Or <andrewor14@gmail.com>

Closes #846 from andrewor14/shell-master and squashes the following commits:

2cb81c9 [Andrew Or] Respect spark.master before MASTER in REPL

(cherry picked from commit cce77457e00aa5f1f4db3d50454cf257efb156ed)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>
Updated scripts for auditing releases

- Added script to automatically generate change list CHANGES.txt
- Added test for verifying linking against maven distributions of `spark-sql` and `spark-hive`
- Added SBT projects for testing functionality of `spark-sql` and `spark-hive`
- Fixed issues in existing tests that might have come up because of changes in Spark 1.0

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

Closes #844 from tdas/update-dev-scripts and squashes the following commits:

25090ba [Tathagata Das] Added missing license
e2e20b3 [Tathagata Das] Updated tests for auditing releases.

(cherry picked from commit b2bdd0e505f1ae3d39c46139f17bd43779ece635)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>