Add Classes & Other Selectors for elementHandledElsewhere()

There was redundant code within `elementHandledElsewhere()` so I refactored it to `executeHandlers()` and added class names as a handler to `elementHandledElsewhere()`.

If we follow the No Selector ID rule in CSS (as well as the notion that IDs are to identify a single element), it makes much more sense to have a `.bypass` class option available to users.

Also added other selectors as a possibility (e.g., div[id^="bypass-"]). This will ignore the function side. 

So the addictions can be used as such:

```javascript
specialElementHandlers = {
	// element with class of "bypass" - jQuery style selector
	'div[id^="bypass-"]': true,
	'.bypass': function(element, renderer){
		console.log('.bypass');
		// true = "handled elsewhere, bypass text extraction"
		return true
	}
}
```