Option to filter out DOM nodes

Most of the time I want to grep for something I see in the HTML, to see if I can find a corresponding data object (model) somewhere in the JS structures.

Traversing DOM objects slows the search down significantly, so I added an option 'allow_dom' (default true) to filter out DOM objects from the search path. This allows me to set the search depth to around 7 and still receive the needed results in a matter of seconds.

Perhaps this is a feature useful enough to be merged?