Adds HTML5 drag/drop proxy events to a Ractive element.

Code is loosely inspired by these updates to this module. Difference with this module is that it applies events to a given element rather than to all its children, and it doesn't clobber the element's draggable attribute.

1. Require or include Ractive and this project
2. Add on-dragndrop='foo' to something in the template
3. Add ractive.on('foo', fn) in your source

	var ractive = new Ractive({
		el: '#container',
		template: '<div on-dragndrop="DND" draggable="true">{{text}}</div>',
		data: {
			text: 'Drag me!'
		}
	})
	
	ractive.on('DND', function(event) {
		console.log(event)
	}

See live demo or example/index.html for a full example.

• type - One of: [ start, enter, over, leave, drop, end ]
• context - Ractive context of the event item
• keypath - Ractive keypath of the event item
• node - HTML element of the event item
• original - the original DOM MouseEvent

Note that the event item is the item being dragged for start/end events, and the item you're dragging to for all the others.