[HEAD-542] usb-headnode should have a configurable source URL
[HEAD-542] usb-headnode should have a configurable source URL

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