Lamp 0.19.0

• One wish can now be several apps that work together, with one chat: a TV app with the iPhone app that controls it,
  or a Mac, iPhone, Android and TV app side by side. A wish that could be for more than one device, and doesn't say
  which, asks you first, and "make it work on my TV too" adds an app without rewriting the one you have.
• The apps of a wish see each other and send each other messages, and phones talk straight to the TV, so a phone can
  hand the TV a game, a photo or a song.
• Share a whole wish: every app in it goes in the file, TV apps included.
• A new app's first build reads as chapters in the chat: each part of the plan, ticked as it's done, with what was
  said and done under it, and Lamp's question where it was asked.
• Xbox games have sound, and Xbox apps play sound from the start instead of after the first button press.
• A new starter wish, New York: Mr.doob's Slop New York, all of Manhattan to explore on foot, by car, by bike or by
  helicopter. It takes Drive Anywhere's place on new desks; add it from Starter wishes at the end of the desk.
• A wish made by a newer Lamp is left as it is, shown faded on the desk, instead of being opened as an empty one.