cdm.js exported functions to not process.exit()

[atheurer]

Exiting on an error was fine for CLI utils, but does not work well when you have a daemon. Functions used here will eventually be called by a node.js daemon which provides a REST API for queries. The daemon should not just exit when faced with an error, but send an error to the client and continue operation. In order to do so, all functions in cdm.js can no longer just exit. All functions will need to return a status, and in turn API calls to this daemon will need to return a status as well.