[tex-live] Bugs in install-tl for win32

[Karl Berry]

    Could it be that your tar does not support some options? 

Doesn't our installer use only our own self-provided tar (and wget and
perl) on Windows?  So Dan's installed versions wouldn't be relevant.

Given all of Dan's reported download problems, I rather suspect what was
downloaded was corrupted, hence the "file not found in archive".

Did we put in a test to see if a downloaded file was actually usable
(could be decoded by lzma + tar)?  I know I asked for that, and I also
know I never implemented it myself :(.

    Maybe we can fix this by staying with one selected mirror.

This would clearly be desirable anyway, to avoid version skew among
mirrors.

Meanwhile, -url is the way to go.

Thanks,
k