Avoid creating device objects for listing ids
Removed some wrong calls to Writes() when building API
Set up URLs to run the app against a local server.

In addition to this commit, it is necessary to set

  "hostname"         : "0.0.0.0"
  "port"             : "8080"
  "personaHostName"  : "0.0.0.0:8080"

in your config.json.
WIP: Command scaffolding
WIP Store commands in db
Receive commands on the server.
Debugging code.

TODO:

- Refactor form in app/index.html
- Figure out how to add new commands
- JSON representation of a device should not include commands,
but maybe the URL to commands. Or nothing at all (which doesn't break
tests!), then have API call to query commands.
- addDevice needs to either delegate to serveDevice somehow, or not
return commands