Required javascript modules fail to load on a clear cache (or new document)

I have observed this issue a while back, when we started using requireJS in wysiwyg to inject the tree widget.

Some issue manifestations so far are:

• Failing to load the wysiwyg editor and getting stuck in an endless loading screen (spinning wheel inside the wysiwyg container)
• Breadcrumbs siblings tree listing no entries (having a reduced size)
• "Pages" tree on the homepage loading with a 3+ seconds delay (or even failing to load entirely and displaying only the dashboard "Pages" heading)
• etc.

Also, to make the loading fail completely, I`ve noticed that you can perform 3+ quick consecutive hard refreshes (CTRL+SHIFT+R on Firefox) which will result in a long loading (~10 sec) with the "Transfering data from localhost..." message and then it will stop, resulting in the trees not being available.

As far as I can see, there are some issues with requirejs in obtaining the required javascript code that occurs when you hard refresh a page (clear cache) or (on my machine at least) even when landing on (or creating) a new page.

Maybe it's an usage problem on our end and I, personally, blaim requireJS' CDN system for specifying the location of your module, which, AFAIR from working with it on the syntax highlighting app, can cause issues and wait for the default 7 seconds (IIRC) timeout. AFAIK, we prefer some CDN resources over the bundled ones, so that might be a place to start looking.

Definitely needs investigation since we are increasing its usage (mainly through the usage of the tree widget).