Fixes #231 (Add ability to override configuration parameters)

Adds ability to specify configuration parameter values that should be used to override the configuration values that are chosen by Hanlon during the initial setup of the client/server configuration files by the `hanlon_init` script. With these changes in place, this issue should be resolved (since these parameters can be overridden during execution of the `hanlon_init` script using either a YAML file or a JSON string specified via the command-line).