TODO:
      X * Geometry isn't always updated when panel size changes.
      x * Remove debugging code (makes everything slow).
	* Tooltip or other popup to alert user that buttons are locked (with a "don't show this again" checkbox).
	* Docs.
	* Use old quicklauncher config file if found.  #77959
      X * "Add application" context menu should add the new application at the index of the button that summoned the context menu.
      X * Make sure to always have a little space to drop things on, even when there are no buttons.
