CDAP-611: Ported Netlens app to use Services instead of Procedures

@ParthGandhi this RP contains all changes described in https://github.com/caskdata/cdap-apps/pull/39 + fixes according to PR comments
I think it's better to say in a same way as in documentation: "Services can be run in a Cask Data Application Platform (CDAP) Application to serve data to external clients." http://docs.cask.co/cdap/current/en/developers-manual/building-blocks/services.html