[tlbuild] tlmgr

[Karl Berry]

Hi Bob,

    Several occurrences of w32 should probably be updated.

We've tried to change all the user-visible --options and strings and doc
now (after tonight's build). We left some "internal" option names and
identifiers and such with "w32" since it seemed like an unnecessary
complication for now. Something to tweak after the release.

Let me know if anyone finds more ... I don't doubt there are some.
--thanks, karl.