Using a command line adding dscp (instead of tos) you can:
--dscp EF,CS1,etc.
--dscp 0x08
--dscp 63
These will provide the correct shifted left 2 tos value for these, and
for people that think in terms of dscp values, this is a goodness.
Having this option available lets an enduser clearly distinguish between
an old version of iperf with a non-working --tos facility, vs a
version where it works, with something saner that lets just specify
the dscp.
I did not come up with a good -? option for it, and used -5 internally.
