Move log configuration to config.yaml.
Improve readability.

Remove pulsar-rest-api.js. Pass to Server instance of Config instead of Config.asHash.
Optimize server setup.
Logger.createLog -> Logger.configure.
Handle the case when logger is used before it is configured.
Rename `var log` to `var getLog`.
Merge pull request #51 from vogdb/issue-51

Allow to change logdir/logfile path.