Submitted changes for draft-09, transferring to Spencer.

We have the text.  If there are are no issues with it in the next few days, I
will  submit the change.

I'll create a proposal to address this.

If someone wants to set sticky, setuid, setgid, or other bits not
in 0777 they should be able to do it. A new form of the mode attribute
that takes a bit mask which is the set of bits to leave unperturbed (or
alternatively the set of bits to change) as well as the mode, would allow
semantics like chmod +s or chmod +l to work.