mod_http_oauth2: Reject non-local hosts in more code paths We're not issuing tokens for users on remote hosts, we can't even authenticate them since they're remote. Thus the host is always the local module.host so no need to pass around the host in most cases or use it for anything but enforcing the same host.

Prosody 0.12 added an API allowing modules to report their status. This
module allows reading these statuses via HTTP for use in monitoring.

```
$ curl http://prosody.localhost:5280/status
{
   "example.com" : {
      "c2s" : {
         "message" : "Loaded",
         "type" : "core"
      }
   }
}
```