Add tests for the utility methods in protocols.py

Created by: agraubert

Just to ensure testing of each unit of code, the utility methods of protocols.py should be checked for consistency (ie the byte<->int conversion methods, the command packing and unpacking methods, etc). The worker methods and assignment are tested by the SecureServer tests. I think this is important, and should be part of Security 2.0, but it should happen last, after all other changes for the release have merged to dev.