LIVEOAK-217 Reduce the default mongo launcher journal size
 + Added README
 + Did slight refactoring, and applied hyphenated JSON key names instead of camel-case
 + Renamed mongoLauncher.json to mongo-launcher.json (make sure to remove existing mongoLauncher.json in your conf/extensions)
 + Added use-small-files, and extra-args
 + Fixed dist assembly to not include mongo-launcher.json