Removed writer's count of bytes written and renamed a method.

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

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

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

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

api/net/sf/briar/api/serial/Writer.java

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

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

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

components/net/sf/briar/protocol/writers/AckWriterImpl.java

...onents/net/sf/briar/protocol/writers/BatchWriterImpl.java

...onents/net/sf/briar/protocol/writers/OfferWriterImpl.java

...ents/net/sf/briar/protocol/writers/RequestWriterImpl.java

...net/sf/briar/protocol/writers/SubscriptionWriterImpl.java

...ts/net/sf/briar/protocol/writers/TransportWriterImpl.java

components/net/sf/briar/serial/WriterImpl.java

test/net/sf/briar/protocol/AckReaderTest.java

test/net/sf/briar/protocol/BatchReaderTest.java

test/net/sf/briar/protocol/RequestReaderTest.java

test/net/sf/briar/serial/WriterImplTest.java