Implement test executable for FFI completeness

[qdot]

Need a test executable that will:

• Add a special test device manager we control, to monitor device access
• Bring up a server
• Expect a certain chain of commands to be run from the FFI client to the server, to check functionality
• On client disconnect, will report methods that were not called

This would be handy for implementing new FFI implementations and giving a sort of "rosetta stone" approach for API creation.