laravel/framework — pull request #3857 by jdkanani (2014-03-11 17:22:41+00:00)
Title: Add onRaw support

`onRaw` would be useful like `whereRaw` in many cases while using db function on `on` clause.
```php
Post::with('user')
->join('posttags', function($join){
$join->onRaw("FIND_IN_SET(tag_id, tags)"); // just an example
});
```