fence_sanlock: various fixes and changes
    
    - change device arg name to path
    - add some metadata descriptions
    - in off, make request after first acquire fails
    - in off, always success after acquire works
    - in off, check if victim re-acquired cleanly
    - in off, check if already off at start
    - in status, use ^timestamp
    
    Signed-off-by: David Teigland <teigland@redhat.com>