Last week I was compelled to investigate celebratory sounds coming from the living room where my 13 year old was playing, Call of Duty 48: That Will Be $50.00 Please Gavin: Whoo Whoo! YEAH YEAH! Awesome! Me: What? Did you win? Gavin: I just did a cross map tomahawk kill! Me: Whut? Gavin: A. Cross. …