Fix compile, make system able to start with failure.
Cleanups of various kinds

* Remove lager log entry lines for now and replace them with the error_logger. We don't
  want to be dependent on lager just yet.
* Split the Kademlia space into dht_id for its computation. This is probably not needed,
  but it removes a lot of functions from the dht module which shouldn't be there.
Heed the gen_server documentation and ignore the reply from reply/2.