slugos-init: make /linuxrc use disk uuids, remove .recovery stuff in 0.10

slugos-init: make /linuxrc use disk uuids, remove .recovery stuff in 0.10
 - the /boot/disk bootstrap now mounts -U uuid if one is available from
   turnup.  turnup checks disk for blkids and no longer complains about
   .recovery, /boo/* no longer create .recovery or check for it on boot;
   disconnect the disk or the network to boot to flash on a semi broken
   system.