Changed maximum packet and message sizes in preparation for new

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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