util.py: replace mountCgroups with checkCgroups, which
returns the cgroup version (cgroup, cgroup2)
node.py: handle cpu.max='quota period' for cgroup2
vs. cpu.{cfs_quota_us,cfs_period_us} for cgroup
net.py: make _iperfVals more robust in the case of a missing
UDP ACK
examples/cpu.py: user _iperfVals to handle new iperf behavior
of no output from telnet
lantz
b762d0bf96