Inbound cleanup (pep8, indenting, imports).
Inbound: fix security manager problem when not validating sender.
Inbound: add unwrapping setting tests.
Inbound: add secruity tests.
Inbound: use more specific exceptions.
Inbound: extract inbound code into inbound method.
Inbound: extract user getting code into get_user method.
Inbound: refactoring cleanup.