Endpoint controllers

Hi,

This is a cleanup (to make it work with latest version of Swagger-PHP and ZF 2). It also adds a controller that return json so that we can use Swagger-UI with it. Basically, those two URLs : /api/docs and /api/docs/resourceName return Json code that could be consumed by Swagger-UI.

I initially thought about adding console commands to generate HTML file directly but it was too much work for no benefits.

I'm not sure it will work as it, the Swagger-PHP library lacks of flexibility somewhat.

Later, I think it could be good to:

- Allow to set cache
- Reduce all those annotations by reusing some annotations (for instance from Doctrine entities and so forth).