Well, there’s Rick Foucheaux in a chair playing a dead guy again. And look — Sarah Marshall is acting crazy as only she can. And come to think of it, this is another Sarah Ruhl play that concerns itself with the afterlife. Is there anything original happening here? Yep. Pretty much everything, actually. Dead Man’s Cell Phone, the world-premiere Ruhl now onstage at Woolly Mammoth, tests your patience a bit in the early going,…