Moved message verification and DB writes off the IO thread.

api/net/sf/briar/api/protocol/ProtocolReader.java

api/net/sf/briar/api/protocol/UnverifiedBatch.java

components/net/sf/briar/protocol/BatchFactoryImpl.java

components/net/sf/briar/protocol/BatchReader.java

components/net/sf/briar/protocol/MessageReader.java

components/net/sf/briar/protocol/ProtocolModule.java

...ents/net/sf/briar/protocol/ProtocolReaderFactoryImpl.java

components/net/sf/briar/protocol/ProtocolReaderImpl.java

components/net/sf/briar/protocol/UnverifiedBatchFactory.java

...nts/net/sf/briar/protocol/UnverifiedBatchFactoryImpl.java

components/net/sf/briar/protocol/UnverifiedBatchImpl.java

components/net/sf/briar/protocol/UnverifiedMessage.java

components/net/sf/briar/protocol/UnverifiedMessageImpl.java

.../sf/briar/transport/batch/BatchConnectionFactoryImpl.java

...net/sf/briar/transport/batch/IncomingBatchConnection.java

...t/sf/briar/transport/stream/IncomingStreamConnection.java

...t/sf/briar/transport/stream/OutgoingStreamConnection.java

...nents/net/sf/briar/transport/stream/StreamConnection.java

...f/briar/transport/stream/StreamConnectionFactoryImpl.java

test/net/sf/briar/ProtocolIntegrationTest.java