Adding a MERC configuration.
Issue #6: Updated Mongoose to v 5.1

- listeningPorts removed in favor of listeningPort
- listeningPort can be changed while server is running
- removed mongooseDaemon:didCompleteRequest:withStatusCode: and
  mongooseDaemon:shouldLogMessage: as they are no longer aligned with
mongoose callbacks.
- suppressing shorten-64-to-32 warnings since mongoose is full of them.
Merge branch 'master' into dev