Separate core API and API extensions

[danbim]

Design a mechanism to enhance a core API with an arbitrary set of API extensions. The core API should only contain the following primitive functionalities:

• listen (add/remove controller)
• send
• reset
• flash
• check-alive
• set-channel-pipeline
• get-supported-channelhandlers

All other functionalities (such as the Node APIs virtualization features) should be accessible through some other Web service endpoint. The core API should therefore provide a method to discover the available API extensions which returns an extension self-description containing:

• Name
• Description
• Version
• URL to the WSDL file of the extension