Here is a glimpse at each of the 49ers' regular-season matchups: Sept. 7, at Dallas Cowboys (1:25 p.m., FOX): Never in their 33-game storied rivalry have they opened a season against each other. Tony Romo keyed the 49ers' first loss under Jim Harbaugh in Week 2 of 2011. Sept. 14, vs. Chicago Bears (5:30 p.m., NBC): Not [...]