Merge pull request #443 from tdas/filestream-fix

Made some classes private[stremaing] and deprecated a method in JavaStreamingContext.

Classes `RawTextHelper`, `RawTextSender` and `RateLimitedOutputStream` are not useful in the streaming API. There are not used by the core functionality and was there as a support classes for an obscure example. One of the classes is RawTextSender has a main function which can be executed using bin/spark-class even if it is made private[streaming]. In future, I will probably completely remove these classes. For the time being, I am just converting them to private[streaming].

Accessing underlying JavaSparkContext in JavaStreamingContext was through `JavaStreamingContext.sc` . This is deprecated and preferred method is `JavaStreamingContext.sparkContext` to keep it consistent with the `StreamingContext.sparkContext`.
(cherry picked from commit 2a05403a7ced4ecf6084c96f582ee3a24f3cc874)

Signed-off-by: Patrick Wendell <pwendell@gmail.com>
Merge pull request #442 from pwendell/standalone

Workers should use working directory as spark home if it's not specified

If users don't set SPARK_HOME in their environment file when launching an application, the standalone cluster should default to the spark home of the worker.
(cherry picked from commit 59f475c79fc8fd6d3485e4d0adf6768b6a9225a4)

Signed-off-by: Patrick Wendell <pwendell@gmail.com>