Bunch of changes to the new Flume stuff

- Changed public API
- Changed Spark Sink package for o.a.s.flume.sink to o.a.s.streaming.flume.sink
- Added Java unit test to make sure Java API works with Java
- Added Scala example (Java example left for future)

Array[XYZ] in Scala is same as Java XYZ[]. So this can be perfectly used. See the JavaFlumePollingStreamSuite. :)