PhpDoc return type for fluent style methods

I would like to change the return type of all fluent style methods to `@return $this` (instead of `@return ClassName`). Look here for more infos: https://github.com/phpDocumentor/fig-standards/blob/master/proposed/phpdoc.md#keyword, 15.

PhpStorm is supporting this very well, but I don't know for the other main PHP IDEs.
So maybe we should use a compat notation: `@return ClassName|$this`.

What do you think about this?

### Example:

Before:

![bildschirmfoto 2014-03-02 um 20 01 25](https://f.cloud.github.com/assets/330436/2304938/491020da-a23d-11e3-8710-c9cdb0689389.png)

After:

![bildschirmfoto 2014-03-02 um 20 02 21](https://f.cloud.github.com/assets/330436/2304939/5144498e-a23d-11e3-8b19-2f39c46e3fc3.png)