Lazy-loading of css stylesheet and js scripts

This patch adds the xLazyLoader. Not sure where we should use it so far though, but it does provide the command, so you could tell the client to load collapse.js. You can see it in action on the Drupal 7 branch:
http://head.robloach.net/dialog/example

When you click on one of the contextual links (like configure block), it loads up the additional JavaScript so that the vertical tabs work.

In order for forms to work in a Dialog we need it to be able to lazy-load both css and js files.
Would it make sense to provide a function to automatically load css and js files required by forms (through a function), if you specify the Dialog is opening a form?

Oh snap, check out what tha_sun is proposing....... #561858: [Tests added] Fix drupal_add_js() and drupal_add_css() to work for AJAX requests too by adding lazy-load to AJAX framework.

I'm wondering if the lazyloader should be removed from the module now that the ajax system handles it. It seems to be double-loading css and js that's already on the page. :(

Do it! ;-)

Dialog 6.x is no longer supported.