sanlock: read and write apis for lockspace and resource
    
    - write_lockspace includes an arg to specify the io timeout
      written in the disk record.
    
    - read_lockspace provides the io timeout from the disk record.
    
    - read_lockspace/resource only require path and offset input.
      If host_id is zero or unspecified, host_id 1 is used.
      If other parameters are specified, they are used and verified.
    
      # sanlock client init -s s1:0:/dev/vg/leases:0
      # sanlock client init -r s1:r1:/dev/vg/leases:1048576
    
      # sanlock client read -s ::/dev/vg/leases:0
      s s1:1:/dev/vg/leases:0
      io_timeout 10
    
      # sanlock client read -r ::/dev/vg/leases:1048576
      r s1:r1:/dev/vg/leases:1048576:0
    
    Signed-off-by: David Teigland <teigland@redhat.com>