Web API to configure broadcast stream and path/key

Rework from previous attempt. Building on changes made to XConfig parsing to support single line JSON. 

If a URL in services.config starts with http or https it assumed that this is a web api which returns an actual Broadcast URL and Broadcast Path (ie the same information that would be required to start up a custom stream). The web API response is assumed to look like (other data would be ignored):

{"data":{"stream_url":"rtmp://some_url", "stream_name": "some-name"}}

Comments from previous pull attempt addressed.