Add functionality to parse text files to RDDs

Uses Scala's Parser Combinators to intelligently try to smart raw text files into RDDs. The idea is that the text files can be comma-separated or semi-colon separated (eg), so in order to group those cases I created a combination of parsers. 

This was also meant to serve as a proof of concept for running things over Spark. 


note to try various curried and uncurried form as per discussion yesterday (not a dealbreaker for pr, but we should get to the bottom of this)