The context is more important than the content in “Norm Macdonald: Nothing Special,” a spare one-man comedy show that the former “Weekend Update” anchor, knowing that he was ill, wrote and performed in a single take at home alone before his death in September. The posthumous release provides a fitting and deeply personal tribute, as well as a primer on the art of stand-up.The context is more important than the content in “Norm Macdonald: Nothing Special,” a spare one-man comedy show that the former “Weekend Update” anchor, knowing that he was ill, wrote and performed in a single take at home alone before his death in September. The posthumous release provides a fitting and deeply personal tribute, as well as a primer on the art of stand-up.