[SPARK-2759][CORE] Generic Binary File Support in Spark

The additions add the abstract BinaryFileInputFormat and BinaryRecordReader classes for reading in data as a byte stream and converting it to another format using the ```def parseByteArray(inArray: Array[Byte]): T``` function.
As a trivial example ```ByteInputFormat``` and ```ByteRecordReader``` are included which just return the Array[Byte] from a given file.
Finally a RDD for ```BinaryFileInputFormat``` (to allow for easier partitioning changes as was done for WholeFileInput) was added and the appropriate byteFiles to the ```SparkContext``` so the functions can be easily used by others. 
A common use case might be to read in a folder 
```
sc.byteFiles("s3://mydrive/tif/*.tif").map(rawData => ReadTiffFromByteArray(rawData))
```
@mateiz I agree that makes sense. Originally I used the global configuration file so I could call it from PySpark, as in ``sc.newAPIHadoopRDD('FixedLengthBinaryInputFormat',..., conf={'recordLength': '100'})``. But we can just add the new ``binaryRecords`` to PySpark directly (probably in a separate PR), and have record length an argument as you suggest.