Last night, every concrete beam in the massive Madison Square Garden shook as Prince brought his “Welcome 2 America” show to the city of New York, the last leg of his tour. He played every hit marvelously, proving although he’s a megalomaniac, a lunatic or one big asshole, in short, that he’s still the purple guitar god. What came as a total surprise to everybody however was when Cee-Lo Green took the stage next to…