There’s one thing to be said for the MBTA’s Fiscal and Management Control Board, it has a puckish sense of humor. As the Herald’s Sean Philip Cotter and Mary Markos reported, the board met Monday and approved a spate of spendy resolutions. First up: a massive overhaul of the Commuter Rail, with electrification of main Commuter Rail lines and trains running every 15 to 20 minutes all day, rather than the current handful of trains headed into Boston in the morning and then back out in the evening. But the piece de resistance is a tunnel that would link North and South stations. Marvelous stuff, though we’re not quite sure why all-day, every-20-minute trains are needed for the Newburyport/Rockport Line. Perhaps Rockport is the next hot nabe? And a tunnel linking North Station with South would be a boon for getting around the city efficiently. The last time it was easy to traverse the Seaport and North End areas using public transportation was in the heyday of the Atlantic Avenue El, which ran from 1901 to 1938. But here’s the tricky bit — the Commuter Rail improvements come with a  $10 billion to $28 billion price tag, and that North/South Station tunnel rings up at nearly $30 bill...