Fix checksum odd byte handling.

Add error log to SKB validation.
Resolve sequence number immutable increments.
Move data source port generation into socket per upstream.
Achieve basic transmission wrapped in PGM protocol.

Author: steve-o

run.sh pgmrecv.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+java \
+	-cp log4j-api-2.0-beta6.jar\;log4j-core-2.0-beta6.jar\;target/classes \
+	-enableassertions \
+	pgmsend $*