Support dataset labels

[fulldecent]

I am using this dataset:

var data = {
    labels: [],
    datasets: [
        {
            label: "PMT",
            fillColor: "rgba(187,0,25,0.5)",
            data: [65, 59, 80, 81]
        },
        {
            label: "ATC",
            fillColor: "rgba(29,74,124,0.5)",
            data: [28, 48, 40, 19]
        },
        {
            label: "RUSH",
            fillColor: "rgba(72,164,218,0.5)",
            data: [28, 48, 40, 19]
        }
    ]
};

And get this chart:

Was expecting the PMT, ATC and RUSH labels to be shown on the screen.

Fiddle: http://jsfiddle.net/jxnper69/

[macdabby]

I was having the same issue and created a patch: #657

[fulldecent]

related #838