Allow array of event handlers in View#delegateEvents.

It can be useful to define multiple independent event handlers for a single event + selector combination. This helps promote reusable event handler methods, for example:

```javascript

Backbone.View.extend({
  events: {
    "mouseover .map":    ["showTip", "moveTip"],
    "mousemove .map":    "moveTip",
    "mouseout .map":     "hideTip"
  }
});