test-archive: silence stupid messages from GNU tar
Recent versions of GNU tar have apparently decided they're old enough
that it's ok for them to prattle on senselessly about things no one
cares about without anyone objecting. We object; apply duct tape.
adding file
% create a second head
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
created new head
% failing merge
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg up --clean' to abandon
% resolve -l, should be empty