So Savion Glover was central to the success of the animated “Happy Feet.” But John Rockwell wonders why he doesn’t get higher credit in the film. “I wasn’t at the ‘Happy Feet’ negotiating table, so I can hardly impugn the tactics or skill of Mr. Glover and his negotiators in these matters. Maybe they gave way on credit placement in exchange for more money. But for an admirer of him and of tap and of dance, he seems to have gotten a ludicrously raw deal.”