SSU2: Stubs for relay and peer test (phase 2)

...rc/net/i2p/router/transport/udp/EstablishmentManager.java

...c/net/i2p/router/transport/udp/InboundEstablishState.java

.../net/i2p/router/transport/udp/InboundEstablishState2.java

...src/net/i2p/router/transport/udp/IntroductionManager.java

.../net/i2p/router/transport/udp/OutboundEstablishState.java

...net/i2p/router/transport/udp/OutboundEstablishState2.java

router/java/src/net/i2p/router/transport/udp/PeerState2.java

...er/java/src/net/i2p/router/transport/udp/SSU2Payload.java

router/java/src/net/i2p/router/transport/udp/SSU2Util.java

...r/java/src/net/i2p/router/transport/udp/UDPTransport.java