Franco Dragone has reinvented theatre in Vegas. After a string of hits, he’s undertaken his most ambitious show yet, at Steve Wynn’s new mogul-named hotel. “Dragone’s new water-based extravaganza — which opened here last weekend — is at once deeply troubled and proudly uncompromising; arrestingly original and inevitably derivative; dripping with heart and strangely removed. You could say much the same about the much-hyped Wynn Las Vegas Hotel, wherein whimsy has been left outside on the street. And yet “Le Reve” also is at war with its surroundings.”