Improve performance with JavaScript lazy loading.

I'd prefer not to use the AddThis button because of some of their questionable business practices, however the AddToAny button performs rather poorly. The primary reason being inline JavaScript that blocks page loading/rendering. The good news is that there's opportunity for easy improvement. Currently the module adds inline JS during page load. This blocks the page load, and simply adds more things that need to happen before the page is done loading. But since only the button image is required for page rendering, the JavaScript can be lazy loaded after the page is finished rendering and in the background. Here's an example:

$(window).load(function(){
  var head = $("head").first() || document.documentElement;
  var script = document.createElement('script');
  script.type = 'text/javascript';
  script.async = true;
  script.src = 'some_script.js';
  head.insertBefore(script, head.lastChild);
});

This mimics the technique used by Google Analytics but more jQuery oriented. You can use the same technique to load CSS, iframes, or whatever else.