Tonight’s second installment in this gorgeous, astoundingly photographed new nature series is called “Mountains,” and it includes footage capturing, for the first time, a snow leopard up close and personal, atop the world, with photography so breathtaking (taken with remote, movement-triggered cameras) that you absolutely must see them. As they say, there’s no leopards like snow leopards. And in case you missed last week’s premiere episode of Planet Earth II, it&rsq