pretesting: tlmgr

[Karl Berry]

    It may be better to disable updating tlmgr from the shell altogether
    on windows, but considering the release schedule it may be better to
    postpone this till after release. Karl?

How invasive, and on the other hand how desirable, would this change be?

It'll be at least through the weekend before we do the final
freeze. Aside from asy madness, just got a couple more buffer overflows
that I feel duty-bound to fix :(. -k