Get working scanning over rgpiod

This includes getting a list of chips, their line numbers, enumerating
the properties of the lines/pins, and providing to the user the list of
valid pins to connect to relays.

It also includes reworking the fake relay system and the configuration
file.

I believe this ends the rampant refactoring and I'll now stabilize out
some features.

templates/index.template.html

@@ -6,7 +6,7 @@
   <h2>Relays</h2>
   <ul>
   {% for relay in relays %}
-  <li><a href="/relay/{{ relay.id }}">{{ relay.name }}</a> - {{ relay.state }}</li>
+    <li><a href="/relay/{{ relay.id }}">{{ relay.name }}</a> - {{ relay.state }}</li>
   {% endfor %}
   </ul>
 {% endif %}