Update the core diagram of the Service Manager
Refactor the client method for sending out messages as a "simple
requestor"

* Use the simple_request method of ServiceManagerClient for sending out
  simple messages, e.g. management messages
The client receives results as a JSON object
Add a client method for subscribing for updates from a publisher

* The client waits for a period of time after that time it simply
  returns the messages it got from the publisher
service-mgr-client waits for updates from the Service Manager Result
Publisher

* Add a --debug option
* Add a --wait-time option