largefiles: make linear update set unsure largefiles normal if unchanged 'hg update' would hash all 'unsure' largefiles before performing the merge. It would update the standins but not detect the very common case where the largefile never had been changed by the user but just had been marked with an invalid dirstate mtime to make sure any changes done by the user in the same second would be detected. The largefile would remain in that state and would have to be hashed again next time even though it still not had been changed. Sad trombone. Instead, for largefiles listed as 'unsure' or 'modified', after updating the standin with the actual hash, mark the largefile as normal if it turns out to not be modified relative to the revision in the parent revision. That will prevent it from being hashed again next time.