SPRINGFIELD — Gov. Patrick J. Quinn’s hand might be tired. The Chicago Democrat has acted on more than 50 bills this week, vetoing a couple but signing most into law in order to meet a 60-day deadline mandating the measures become law automatically if he doesn’t put pen to paper. Among the highlights are bills he signed that aim to prevent workplace discrimination against pregnant women and to curb GPS tracking by law enforcement. And a year after approving a bill to up the speed limit to 70 mph …