Removed unnecessary Raw interface.

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/Message.java

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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