Add json rest api

[ajmas]

Add a JSON based REST API, so the directory can be leveraged by applications, other than web browsers.

[zenermerps]

There is already an API, documented here. Altough the current live version does not have an API. This repository is for the rewrite of the directory, which is currently being tested at dir-test.xiph.org.

[ePirat]

Please note that the current API is not final, it can change at any time, this is all a work in progress.
Feel free to review the current API docs and suggest changes or improvements (in separate tickets).

[ajmas]

Thanks I will do that. I can use this current issue tracker?