SSU2: Start of packet handling

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

...java/src/net/i2p/router/transport/udp/PacketBuilder2.java

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

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

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

...r/java/src/net/i2p/router/transport/udp/SSU2Bitfield.java

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

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