The National Football League’s offseason of labor unrest neared its end Thursday evening when the league’s owners approved a 10-year collective bargaining agreement and conditionally lifted their four-month lockout of the league’s 2,000 players. The owners said team facilities would re-open this weekend and training camps and free agency would begin next week — if the players follow suit and ratify the labor deal as well. The 10-year labor deal, which still must be approved by a newly re-certified players union, would split the league’s estimated $9.3 billion in annual revenues fairly evenly.