VANESSA HUDGENS has been single for the longest time, and she wants us to believe that she's happy about it. And why not? Her ex-Zac Efron has been caught canoodling with fellow "High School Musical" co-star Ashley Tisdale, her post-Disney starrer "Sucker Punch" was a sucker at the box office, and now she's chopped up her long lustrous locks and gained 10 pounds to play a homeless teenaged mother in a ...