The Firebase server seems to have changed behavior and is not giving us a List
instead of a Map. This patch switches us back to GitHub, which just serves the
same flat files all the time.

@abarth @collinjackson

Add type annotations in many places.
Fix some identifiers to have more lint-satisfying names.
Make all operator==s consistent in style.
Reorder some functions for consistency.
Make ParentData no longer dynamic, and fix all the code around that.

Make it possible for named routes to be generated on the fly.

To demonstrate this, you can now long-press a stock to open it.

Next steps:

 - transitions between (named) states that follow full material logic,
   e.g. in the case of the stock row to stock page transition, expanding
   the row into a raised sheet of material and expanding it to fit the
   screen, leaving the toolbar in place but cross-fading the old
   contents to the new contents.

 - more information in the stock view.

While I was here I also made Material have an opinion about default text
style, so if you forget to set one, it just uses body1.

Also, fixed bugs introduced recently that made RouteState and MenuRoute
not work properly.

What's important about this code is that it's presenting services outside the
VM, not the particular technology used to present the services.

Converted demo launcher example to library

Converted fitness example to library

Converted hello world example to library

Converted mine digger example to library

Converted stocks example to library

Accessing the network created a race condition that would sometimes cause other
tests to fail.