pynfs RD4 fix headers

Signed-off-by: William Allen Simpson <bill@cohortfs.com>
Signed-off-by: Matt Benjamin <matt@cohortfs.com>
pynfs RD4 fix massive writes

Signed-off-by: William Allen Simpson <bill@cohortfs.com>
Signed-off-by: Matt Benjamin <matt@cohortfs.com>
pynfs RD4 error checking improvements suggested by Frank

Signed-off-by: William Allen Simpson <bill@cohortfs.com>
Signed-off-by: Matt Benjamin <matt@cohortfs.com>