Ability to mark function as deprecated 

https://github.com/nelmio/NelmioApiDocBundle/issues/136

![Screenshot from 2013-03-18 08:41:49](https://f.cloud.github.com/assets/157952/269583/d48485c2-8f9f-11e2-9faf-946a4a7959e6.png)

Example:

    /**
     * @ApiDoc(
     *  resource=true,
     *  description="Add new SMS to Queue",
     *  deprecated=true,
     *  statusCodes={
     *      200="Returned when successful",
     *      403="Returned when the user is not authorized"
     *  }
     * )