While testing TCP & UDP tests (coming soon), I tracked down a bug in the

While testing TCP & UDP tests (coming soon), I tracked down a bug in the
IP addressing scheme
used by xm-test: each machine running network tests is using the same IP
addresses, so two machines
in the same network can cross-pollinate/interfere with each other's tests.

This patch changes the IP addressing scheme to add some randomness. It's
gone through a couple of dozen
passes of xm-test, some on -bridge and some on -route, while xm-test was
running on another box on the same network.

Signed-off-by: Jim Dykman <dykman@us.ibm.com>