Implemented PacketReader, renamed Packet{Reader,Writer}Factory in the

.../sf/briar/api/protocol/writers/ProtocolReaderFactory.java

.../sf/briar/api/protocol/writers/ProtocolWriterFactory.java

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

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

.../sf/briar/protocol/writers/ProtocolWriterFactoryImpl.java

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

...ents/net/sf/briar/transport/ConnectionRecogniserImpl.java

components/net/sf/briar/transport/ConnectionWindowImpl.java

components/net/sf/briar/transport/PacketReaderImpl.java

...nents/net/sf/briar/transport/PacketWriterFactoryImpl.java

components/net/sf/briar/transport/PacketWriterImpl.java

components/net/sf/briar/transport/TagDecoder.java

components/net/sf/briar/transport/TagEncoder.java

test/build.xml

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

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

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