limit.js Code Review
The key differences between a throttled function and a debounced function are that the throttled function can return a value because it is called synchronously and the debounced version cannot because it is used asynchronously.

You have lost that on your throttle implementation. I would at least make the following change:

Function.prototype.throttle = function (milliseconds) {
    var baseFunction = this,
        lastEventTimestamp = null,
        limit = milliseconds,
        lastresult;

    return function () {
        var self = this,
            args = arguments,
            now = Date.now();

        if (!lastEventTimestamp || now - lastEventTimestamp &gt;= limit) {
            lastEventTimestamp = now;
            lastresult = baseFunction.apply(self, args);
        }
        return lastresult;
    };
};