Here’s a thing with the potential to make your Monday less infuriating: The Sandy-flooded Brooklyn-Battery Tunnel is reopening at 6 a.m. Trucks will remain banned until further notice, but all other traffic is good to go in both directions, just like the old days. It’s “yet another step in restoring a sense of normalcy to the region,” said MTA Chairman Joe Lhota. Meanwhile, the R train between Brooklyn and Manhattan will stay down at least another few weeks.