[development] Move all core modules into their own directories.

[drupal]

> did you make any progress with this?
Yes - debugging some code though.

The modules in core in their own directories is a simple script and it
just works. Out of the box in drupal. No code changes required. It just
works.

The theming bits are more complicated. It requires changes to the
modules code, and learning from the form api's changes I've written a
helper tool. Unfortunately still fishing for bugs in it. With luck I'll
have it working within a day or two.