// http://stackoverflow.com/questions/7279567/how-do-i-pause-a-window-setinterval-in-javascript

function RecurringTimer(callback, delay) {
    var timerId, start, remaining = delay;

    this.pause = function() {
        window.clearTimeout(timerId);
        remaining -= new Date() - start;
    };

    var resume = function() {
        start = new Date();
        timerId = window.setTimeout(function() {
            remaining = delay;
            resume();
            callback();
        }, remaining);
    };

    this.resume = resume;

    this.resume();
}