[SPARK-4382] Add locations parameter to Twitter Stream

When we request Tweet stream, geo-location is one of the most important parameters. In addition to the track parameter, the locations parameter is widely used to ask for the Tweets falling within the requested bounding boxes. This PR adds the locations parameter to existing APIs.
There is. I meant that the main problem is the inconsistency between Scala and Java apis. One use `Seq[(Double,Double)]` and other uses `Array[Array[Double]]`. If it is ok, I would revise it.