In a bid to top Avatar as the highest-grossing film of all time, Avengers: Endgame is headed back into theaters—technically it never left, but marketing gonna' market—with six minutes of new and deleted footage. So what does that mean, exactly? The answer, apparently, is not a whole lot, but I'll leave it up to you to decide whether this is enough to get you back into a theater for another go-around with the Russo Brothers' massive Marvel time romp. First up is a tribute to the late, great Stan Lee, the co-mastermind of most …