Add command line options for controlling various bits

too much to list, but now server mode can be handed options
like setting ecn and the diffserv class, and the client
see them.

d@puck:~/git/isochronous$ ./udpburst -S -E -D 32 &
[1] 11266
d@puck:~/git/isochronous$
d@puck:~/git/isochronous$ ./udpburst -f localhost -E -C
64 bytes -- received 32 of 32 -- 32 consecutive 0 ooo 0 dups 0 ect

22222222222222222222222222222222222222222222222222222222222222
d@puck:~/git/isochronous$ ./udpburst -f localhost -E -C -d
64 bytes -- received 32 of 32 -- 32 consecutive 0 ooo 0 dups 0 ect

...............................
22222222222222222222222222222222222222222222222222222222222222