Support choosing destination/source diversity independently.
README.txt: Show how to use the ``-u'' option.
stone.c: Diversity splitted to source/destination diversity.
Obfuscating UDP packets by adding variable size random bytes.
No Encryption applied. DTLS will be a big plus.

README.txt: Add obf option.
stone.c: obfPkg() and deObfPkg() to obfuscate UDP.