Revert "Response callback adds transport information."

This reverts commit 1b35828d5caa755d1acd951c8a42d49513a0d0b0.
Revert "tcpTransport.findNode() auto-fills 'sender.transport'."

This reverts commit dc4fcbbd861f5b24b8a47f25025e19f0b7375a08.
Revert "tcpTransport.ping() auto-fills 'sender.transport'."

This reverts commit 4b9306ad28cb2035c5cc68c8dc59b1bd1556dbce.
Removed docs on auto-filling 'contact.transport'.
Improved test messages.
Implemented tcpTransport.setTransportInfo(contact).
4.0.0