Added "fit" option to scale images to fit container

[Jalon]

Immediately after

                                var whenDimensions = function(width, height) {

Add this block:

                if (data.settings.fit === true)
                {
                    var ratio = Math.min(containerWidth/width, containerHeight/height);
                    width = Math.ceil(ratio * width);
                    height = Math.ceil(ratio * height);
                    $img.css({width: width});
                    $img.css({height: height});
                }