First release checklist

[ef4]

• offer a test-support API that can set initial params and assert about current params (all talking about the strings in the URL, not the values in the models)
• maybe make the param order stable. Right now the URL bar can visually flicker when the order changes as params go from unclaimed to claimed. I don't think this actually breaks anything but it annoys me.'
• backfill some test coverage
• write a readme
  • the core decorator trackedParam
  • the included other types: bool and number
  • how to use createTrackedParam to customize and create more types
  • installation with location setup
  • using with other custom locations
  • how we fall back to a normal tracked property when no routing is around us, and the test facilities for controlling this
• allow configurable interop with classic query params: explicit opt-in and/or opt-out lists of params so that we can decide which ones to handle in this addon and which ones to let the classic router handle.