As discussed with @Superzerocool today, prepare the #web2cit-server's JSON response for consumption from the #web2cit-monitor.
Currently, the API (when asked for a JSON response) sometimes returns an array (of path results), an object (with an `error` property), or just plain text. Make it always return an object with the following properties:
- `info`, including the API version (T313722) and the revid of the configuration files used
- `data`, with the array of path results formerly returned as root object (maybe inside a `results` or `paths` sub-property, to leave room for average score; T313758).
- optional `error`, including an error object with `name`and `message` properties, just like we do already for path-specific errors.
In the array of path results, make sure that for each field we always return the `output`, `test` and `score` properties, even if they are undefined. Convert undefined `output` response to an empty array.