kbench_mod

I just added a special kernel module to the net_test_tools tree,
it allows more accurate measurement of routing lookups.

It does cycle counts across one routing lookup.

The flow key is controlled by module parameters, iif != 0 means
input route lookup, otherwise we do an output lookup.

What's cool is you can jack-up the warmup_count value and then
run insmod under "perf record" and it just works.