Update Quick/Quick submodule.
Update Quick/Nimble submodule.
Update External/Transport submodule.
Remove Transport project.
Remove CocoaFlow/Transport as a submodule.
Add CocoaFlow/MessageTransfer as a submodule.
Add MessageTransfer project and link with targets.
Add changes by Xcode to xccheckout.
Replace FakeTransport with FakeMessageSender.
Use MessageTransfer instead of Transport.
Use fake message sender instead of fake transport.