OAK BLUFFS, Massachusetts (Reuters) - It rained on President Barack Obama's island vacation on Tuesday. After spending the first two days of his August vacation on the golf course, Obama made the most of a rainy day on the Massachusetts island of Martha's Vineyard. First, his motorcade carried him across the island to Oak Bluffs, where he stopped at Nancy's restaurant, picking up a variety of fried delicacies: Shrimp, oysters, onion rings and french fries. SNIP The restaurant is a favorite of his senior adviser, Valerie Jarrett, who is staying at a waterfront home nearby with a sweeping view of...