[HVM-185] merge hvm branch to develop for usb-headnode.
[HVM-185] merge hvm branch to develop for usb-headnode.

kaizengarden/sdc-headnode,kaizengarden/sdc-headnode,kaizengarden/sdc-headnode,joyent/sdc-headnode,numericillustration/sdc-headnode,joyent/sdc-headnode,kaizengarden/sdc-headnode,joyent/sdc-headnode,joyent/sdc-headnode,numericillustration/sdc-headnode,numericillustration/sdc-headnode