FREEPORT, Maine — L.L. Bean’s sales dipped slightly over the past year, forcing the elimination of worker bonuses for the first time since 2008, but the CEO told workers on Friday that changes adopted in recent months are putting the company on a “path to a more prosperous future.” The Maine-based outdoors retailer announced annual revenue of $1.6 billion, which was nearly flat, for its fiscal year that ended on Feb.