Minimalist Toy AMD loader.
This has no great intention of being a full-featured AMD loader, but is more aimed at trying to get a requirejs-like functionality that could fit in a tweet.
This currently requires that this script be loaded into the page first, so that the rqr() function is available, and that any Functions/Objects being loaded are already in the page before they can included with dfn.
In theory, this would work best if all js files are concatenated, with this file in first, and the final require script at the end.
Inspired by other minimalist js projects: