* Resolve duplicate clicking in UI

We add a few features here:

- A "target" function to the header; allowing an item to be located.
- Fixing the "duplicate popup" issue when clicking on something open; it
  now just refocuses te element

It's not perfect; but some comments have been added to indicate the
areas for improvement.

* Allow header-things to be closeable or not
* Added copy and toggle-visibility back
* Allow a little bit more toggle-visibility