Apx server observer extension

[cogu]

The observer extension will be an optional extension to the APX server.

This extension builds an internal view of what is happening inside the APX server. Special APX utilities can then remotely connect to the server and dump this data out.

Examples of what this extension will enable:

• How many APX clients are connected and what APX nodes are attached?
• Remotely copy APX definitions of attached nodes.
• Get a view of all port connectors inside the server, including port connection counts.