HVM-560 remove hvm platform, agents and dataset from default master usb-headnode build.
HVM-560 remove hvm platform, agents and dataset from default master usb-headnode build.

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