When we notice a missing backing service we now throw an exception
and on the html handler we push a setup.html file which has helpful
setup information.
This makes the service mostly self-documenting as it serves plain simple
html pages for error messages which show the end points you can use.
This adds support for the "unspent outputs for address" endpoint.
The very famous bitcore project presents an JSON based service which
presents blockchain data. This application aims to duplicate all the same
functionality but by using Flowee services instead.