When listing messages, the -w option can to some extent decrease the width (by decreasing the Subject: column) but it seems it can't increase the width more that the auto detected one.

Which is a pity because we can't expand the listing to occupy the whole terminal (so that the columns would always be at the same place).

What do you think? May be it could simply widen with spaces the very same Subject: column when increasing?

Requires #114.