fence_scsi: add option for strict verification
    
    Add new option --strict (-s) that will enable strict verification that
    registrations are created on all paths. Previously this was the
    default behavior. Strict verification will compare the number of times
    the registration key exists on a device and the number of paths. This
    is useful when testing multipath configurations. If this option is not
    specified, the verification will simply check to make sure the
    registration keys exist on the device.
    
    Resolves: rhbz#782919
    
    Signed-off-by: Ryan O'Hara <rohara@redhat.com>
    Reviewed-by: Lon Hohberger <lhh@redhat.com>