Fix set selection list logic so that when extracting more sets

a) The selection list does not display default sets already
transferred.

b) Saying 'done' does not seem to mysteriously skip the sets
erroneously shown as selected due to a).

This problem was found by miod@.

In the process

a) Use _setsdone only to record sets that have successfully been
extracted.

b) Don't loop on fetching files if a transfer fails. Just let the user
know, and let the normal logic offer them a chance to extract the
failed sets from the same or different source.

c) Eliminate some (newly) dead variables, especially the global
_osetsdone.

0 files changed, 0 insertions, 0 deletions