Removed SubscriptionUpdate and SubscriptionAck.

briar-api/src/org/briarproject/api/db/DatabaseComponent.java

briar-api/src/org/briarproject/api/sync/PacketReader.java

briar-api/src/org/briarproject/api/sync/PacketTypes.java

briar-api/src/org/briarproject/api/sync/PacketWriter.java

briar-api/src/org/briarproject/api/sync/SubscriptionAck.java

...api/src/org/briarproject/api/sync/SubscriptionUpdate.java

briar-api/src/org/briarproject/api/sync/SyncConstants.java

briar-core/src/org/briarproject/db/Database.java

...r-core/src/org/briarproject/db/DatabaseComponentImpl.java

briar-core/src/org/briarproject/db/JdbcDatabase.java

briar-core/src/org/briarproject/sync/AuthorFactoryImpl.java

briar-core/src/org/briarproject/sync/AuthorReader.java

...core/src/org/briarproject/sync/DuplexOutgoingSession.java

briar-core/src/org/briarproject/sync/GroupReader.java

briar-core/src/org/briarproject/sync/IncomingSession.java

...re/src/org/briarproject/sync/PacketReaderFactoryImpl.java

briar-core/src/org/briarproject/sync/PacketReaderImpl.java

...re/src/org/briarproject/sync/PacketWriterFactoryImpl.java

briar-core/src/org/briarproject/sync/PacketWriterImpl.java

...ore/src/org/briarproject/sync/SimplexOutgoingSession.java