[SPARK-1853] Show Streaming application code context (file, line number) in Spark Stages UI

This is a refactored version of the original PR https://github.com/apache/spark/pull/1723 my @mubarak

Please take a look @andrewor14, @mubarak

I would find it more natural to pass a function that excludes line from Spark code (it just inverts the logic). Something like `internalExclusionFunc`. Then you could have `sparkCoreExclusionFunc` and `sparkStreamingExclusionFunc`. @andrewor14 what do you find more intuitive?