Removed tag from connection context.

api/net/sf/briar/api/transport/ConnectionContext.java

api/net/sf/briar/api/transport/ConnectionReaderFactory.java

api/net/sf/briar/api/transport/ConnectionWriterFactory.java

...s/net/sf/briar/transport/ConnectionWriterFactoryImpl.java

...net/sf/briar/transport/TransportConnectionRecogniser.java

test/net/sf/briar/ProtocolIntegrationTest.java

...briar/protocol/simplex/OutgoingSimplexConnectionTest.java

...riar/protocol/simplex/SimplexProtocolIntegrationTest.java

test/net/sf/briar/transport/TransportIntegrationTest.java