[Gs-code-review] mkdir patch

[Jack Moffitt]

> Before committing this, please check whether -p is in the POSIX
> specification, and ask Nelson Beebe whether it is supported on all the
> Unix-family boxes in his zoo.  I know we had a tremendous amount of trouble
> with the 'install' command, which exists on all Unix-family systems but with
> two different, incompatible specifications, and I don't want the same thing
> to happen again.

I have yet to ask Nelson, but I have tested this now on Solaris, OSX,
BSD, and Linux (which all work).  It seems that two options to mkdir are
standard posix, -p and -m.  

Do you have Nelson's email address handy?

jack.