Make sure we 'sudo kill' our sudo pexpect process in close().

This should more reliably shut down pexpect subprocesses when
build.py exits before completion.
measure loss with udp iperf
use udp with iperf to measure loss. pings are not reliable
Merge pull request #388 from cdburkard/patches/intfOptions

measure loss with udp iperf
Merge pull request #387 from cdburkard/patches/iperf_bw

use udp with iperf to measure loss. pings are not reliable
Merge pull request #386 from cdburkard/patches/cpu_test

Skip test_cpu.py if RT_GROUP_SCHED is not enabled
Wait for crlf after OK/FAILED for better -v output
attach to cgroup first, then mount namespace
add Ryu controller to mininet
Merge pull request #367 from cdburkard/devel/Ryu

add Ryu controller support to Mininet
Merge pull request #391 from cdburkard/patches/fix_popen

workaround: attach to cgroup first, then mount namespace
continue to test cfs if rt is not enabled in kernel