Fix for SPARK-1025: PySpark hang on missing files.
Increase JUnit test verbosity under SBT.

Upgrade junit-interface plugin from 0.9 to 0.10.

I noticed that the JavaAPISuite tests didn't
appear to display any output locally or under
Jenkins, making it difficult to know whether they
were running.  This change increases the verbosity
to more closely match the ScalaTest tests.
Fix ClassCastException in JavaPairRDD.collectAsMap() (SPARK-1040)

This fixes an issue where collectAsMap() could
fail when called on a JavaPairRDD that was derived
by transforming a non-JavaPairRDD.

The root problem was that we were creating the
JavaPairRDD's ClassTag by casting a
ClassTag[AnyRef] to a ClassTag[Tuple2[K2, V2]].
To fix this, I cast a ClassTag[Tuple2[_, _]]
instead, since this actually produces a ClassTag
of the appropriate type because ClassTags don't
capture type parameters:

scala> implicitly[ClassTag[Tuple2[_, _]]] == implicitly[ClassTag[Tuple2[Int, Int]]]
res8: Boolean = true

scala> implicitly[ClassTag[AnyRef]].asInstanceOf[ClassTag[Tuple2[Int, Int]]] == implicitly[ClassTag[Tuple2[Int, Int]]]
res9: Boolean = false
Merge pull request #511 from JoshRosen/SPARK-1040

Fix ClassCastException in JavaPairRDD.collectAsMap() (SPARK-1040)

This fixes [SPARK-1040](https://spark-project.atlassian.net/browse/SPARK-1040), an issue where JavaPairRDD.collectAsMap() could sometimes fail with ClassCastException.  I applied the same fix to the Spark Streaming Java APIs.  The commit message describes the fix in more detail.

I also increased the verbosity of JUnit test output under SBT to make it easier to verify that the Java tests are actually running.
Merge pull request #504 from JoshRosen/SPARK-1025

Fix PySpark hang when input files are deleted (SPARK-1025)

This pull request addresses [SPARK-1025](https://spark-project.atlassian.net/browse/SPARK-1025), an issue where PySpark could hang if its input files were deleted.
change initial gradient descent to BSP+ version
add comments to runMiniBatchSGD
rewrite back to GradientDescent, the loss history slice
Drop Iterator.toArray and use Iterator.duplicate, to reduce the GC overhead