trigger a 'set' event on Collection.set

Example: 

    var c = new Backbone.Collection([
        { id: "1", name: "larry" },
        { id: "2", name: "moe" },
        { id: "3", name: "curley" }
    ]);

    c.on("set", function() {
        // triggers only once in this case
    });

    c.set([
        { id: "1", name: "Larry" },
        { id: "2", name: "Moe" },
        { id: "3", name: "Curley" }
    ]);

This has been something I usually shim for my projects and I know that it is an opinionated change but I figured I'd put it out there. I'd understand if it's not something that you guys don't want to pull.