Check for Url and add Source action

2 steps here

First of all, this patch fixe a potentially bug with library and add a way to check the response of Uri to define if we display a link or an error.

In second time, this patch allow to use source as a keyword when the bot ins mention to get Uri for source code. You need to use class or path.

Example
 ```bash
Marvirc: source Hoa\Websocket
Marvirc: source Hoa\Websocket\Server
Marvirc: source Hoa/Websocket/Server.php
```
Not necessary but easier for maintenance: why not using `Hoa\Http\Request` to build the request? Something like:
```php
$request = new Hoa\Http\Request();

$request->setMethod($request::METHOD_GET);
$request->setUrl($url['path']);

$request['Host']       = $url['host'];
$request['Connection'] = 'close';

echo (string) $request;
```