Go easy on the caffeine if you're heading to the Broadway revival of 'Godspell' that opened on Monday night at the Circle in the Square. The cast of this relentlessly perky production of the 1971 musical, which transformed parables from the Gospels into a series of singable teaching moments, virtually never stops bopping, bouncing, bounding, even trampolining across the stage and up the aisles of the theater. It's like being trapped in a summer camp rec room with a bunch of kids who have been a little too reckless with the Red Bull.