Renamed tasks to handlers.
Added explicit nak handling.
Initial full message prototype code.
Final v0.1 message format.
Merge branch 'feature/registry_update' into develop
Begun refactoring
Cleaned out messages and added utilities.
Shaping up messages again.
Test coverage for base DPNMesage Model.
Improved all messages.  finishes #47853987
test commit finishes #47853987
Test pivotaltracker hook [Fixes #47853987]
Fixed Handlers and ready to test.
[#47666699 #47666903 #47666795 #47877385] Better messag ack and validation.
[fixes #47666699 #47666903 #47666795 #47877385] Checking on fixes and remove unused imports.
Faked some protocol logic to make James feel better.
Merge branch 'feature/refactored_messages' into develop