function bind(target, options) {
    var targets;

    if (typeof target === 'string') {
        targets = document.querySelectorAll(target);
    } else if (typeof target === 'object') {
        targets = [target];
    } else {
        throw new Error('target must be string or object');
    }

    options = options || {};

    for (var i = 0; i < targets.length; i++) {
        bindElement(targets[i], options);
    }
}
Binds the target buttons to automatically enter the
loading state when clicked.

@param target Either an HTML element or a CSS selector.
@param options
         - timeout Number of milliseconds to wait before
           automatically cancelling the animation.
         - callback A function to be called with the Ladda
           instance when a target button is clicked.