Netperf2

Add netperf class as base class.

dd netperf class as base class.

Support netperf client in windows guest.

Support install parameter to control whether install netperf or not.
Hi @FengYang  Met some scp problem if the destination directory not exist:

scp: /var/tmp/: Is a directory
debug1: channel 0: free: client-session, nchannels 1
debug1: fd 0 clearing O_NONBLOCK
debug1: fd 1 clearing O_NONBLOCK
Killed by signal 1.
Do we need to check the  destination directory exist?