nfs4: introduce stateid4#equalsWithSeq()

default equals method checks only 'other' field of stateid as sequence id is
changing. Nevertheless, some times we need check for full equality.

Acked-by: Gerd Behrmann
Target: master
nfs40: update stateid on read and write

Add special ALL-ONES stateid.

Acked-by: Gerd Behrmann
Target: master
nfs4: check state's sequence id when updating lease time

fixes test case from pynfs test suite

Acked-by: Gerd Behrmann
Target: master