Support 'can-swipe' attribute.

[Mateus Castro]

Support 'can-swipe' attribute like "Ion-List", for each "Item" of the Ion-Tree-List, so that it is possible to add "Edits Buttons" inside the list.

Example of 'can-swipe' in action, to show Edit and Share buttons
http://codepen.io/ionic/pen/JsHjf