[SPARK-11440][CORE][STREAMING][BUILD] Declare rest of @Experimental items non-experimental if they've existed since 1.2.0

[srowen]

Remove @Experimental annotations in core, streaming for items that existed in 1.2.0 or before. The changes are:

• SparkContext
  • binary{Files,Records} : 1.2.0
  • submitJob : 1.0.0
• JavaSparkContext
  • binary{Files,Records} : 1.2.0
• DoubleRDDFunctions, JavaDoubleRDD
  • {mean,sum}Approx : 1.0.0
• PairRDDFunctions, JavaPairRDD
  • sampleByKeyExact : 1.2.0
  • countByKeyApprox : 1.0.0
• PairRDDFunctions
  • countApproxDistinctByKey : 1.1.0
• RDD
  • countApprox, countByValueApprox, countApproxDistinct : 1.0.0
• JavaRDDLike
  • countApprox : 1.0.0
• PythonHadoopUtil.Converter : 1.1.0
• PortableDataStream : 1.2.0 (related to binaryFiles)
• BoundedDouble : 1.0.0
• PartialResult : 1.0.0
• StreamingContext, JavaStreamingContext
  • binaryRecordsStream : 1.2.0
• HiveContext
  • analyze : 1.2.0

[SparkQA]

Test build #44758 has finished for PR 9396 at commit 2439d71.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):\n * logInfo(s\"Hive class not found $e\")\n * logDebug(\"Hive class not found\", e)\n

[srowen]

@pwendell you might be a good person to ping about this, or maybe an outside chance of @mateiz or @JoshRosen

[pwendell]

Sean - thanks for doing this. I think these are all reasonable to promote... IMO if it's been around for this many versions, we can't drop them anyways. So LGTM.

[srowen]

Merged to master