Splitup into smaller units

[chessai]

streaming-utils has some heavy dependencies and i (and @fosskers) believe it is worth it to split streaming-utils into streaming-attoparsec, streaming-aeson, etc. for backward compatibility, streaming-utils could just re-export those things.

[fosskers]

http://hackage.haskell.org/package/streaming-attoparsec has been available for a while. Haven't gotten around to pulling out -aeson yet though.