Major League Baseball has proposed limiting free-agent signings to several weeks in December and then from early February in each offseason, along with a ban on trades during the gap in between. The plan aims to create more of an offseason transaction flurry similar to those in the NFL and NBA. The plan offered to the players' association Thursday is contingent on adoption of the salary cap system MLB proposed in May, which the union has vowed never to accept. MLB also proposed lowering the maximum in-season options to the minor leagues from five to four and adopting a system of weekly rosters...