[SPARK-1620] Handle uncaught exceptions in function run by Akka scheduler

If the intended behavior was that uncaught exceptions thrown in functions being run by the Akka scheduler would end up being handled by the default uncaught exception handler set in Executor, and if that behavior is, in fact, correct, then this is a way to accomplish that.  I'm not certain, though, that we shouldn't be doing something different to handle uncaught exceptions from some of these scheduled functions.

In any event, this PR covers all of the cases I comment on in [SPARK-1620](https://issues.apache.org/jira/browse/SPARK-1620).

Author: Mark Hamstra <markhamstra@gmail.com>

Closes #622 from markhamstra/SPARK-1620 and squashes the following commits:

071d193 [Mark Hamstra] refactored post-SPARK-1772
1a6a35e [Mark Hamstra] another style fix
d30eb94 [Mark Hamstra] scalastyle
3573ecd [Mark Hamstra] Use wrapped try/catch in Utils.tryOrExit
8fc0439 [Mark Hamstra] Make functions run by the Akka scheduler use Executor's UncaughtExceptionHandler
(cherry picked from commit 17f3075bc4aa8cbed165f7b367f70e84b1bc8db9)

Signed-off-by: Patrick Wendell <pwendell@gmail.com>
Revert "[maven-release-plugin] prepare for next development iteration"

This reverts commit d08e9604fc9958b7c768e91715c8152db2ed6fd0.
Revert "[maven-release-plugin] prepare release v1.0.0-rc5"

This reverts commit 18f062303303824139998e8fc8f4158217b0dbc3.
Adding back hive support
[maven-release-plugin] prepare release v1.0.0-rc6
[maven-release-plugin] prepare for next development iteration
Fix: sbt test throw an java.lang.OutOfMemoryError: PermGen space

Author: witgo <witgo@qq.com>

Closes #773 from witgo/sbt_javaOptions and squashes the following commits:

26c7d38 [witgo] Improve sbt configuration

(cherry picked from commit fde82c1549c78f1eebbb21ec34e60befbbff65f5)
Signed-off-by: Reynold Xin <rxin@apache.org>
SPARK-1829 Sub-second durations shouldn't round to "0 s"

As "99 ms" up to 99 ms
As "0.1 s" from 0.1 s up to 0.9 s

https://issues.apache.org/jira/browse/SPARK-1829

Compare the first image to the second here: http://imgur.com/RaLEsSZ,7VTlgfo#0

Author: Andrew Ash <andrew@andrewash.com>

Closes #768 from ash211/spark-1829 and squashes the following commits:

1c15b8e [Andrew Ash] SPARK-1829 Format sub-second durations more appropriately

(cherry picked from commit a3315d7f4c7584dae2ee0aa33c6ec9e97b229b48)
Signed-off-by: Reynold Xin <rxin@apache.org>
SPARK-1833 - Have an empty SparkContext constructor.

This is nicer than relying on new SparkContext(new SparkConf())

Author: Patrick Wendell <pwendell@gmail.com>

Closes #774 from pwendell/spark-context and squashes the following commits:

ef9f12f [Patrick Wendell] SPARK-1833 - Have an empty SparkContext constructor.
(cherry picked from commit 65533c7ec03e7eedf5cd9756822863ab6f034ec9)

Signed-off-by: Patrick Wendell <pwendell@gmail.com>
[FIX] do not load defaults when testing SparkConf in pyspark

The default constructor loads default properties, which can fail the test.

Author: Xiangrui Meng <meng@databricks.com>

Closes #775 from mengxr/pyspark-conf-fix and squashes the following commits:

83ef6c4 [Xiangrui Meng] do not load defaults when testing SparkConf in pyspark

(cherry picked from commit 94c6c06ea13032b80610b3f54401d2ef2aa4874a)
Signed-off-by: Reynold Xin <rxin@apache.org>