* Rewrite the layout code to do the layout incrementally in 20 ms passes, to avoid blocking the plasma GUI.
* Show an animation while doing the directory listing and layouting to provide feedback to the user.
* Fix an occasional corruption of the folder title.
* Reduce the number of calls to Plasma::Theme::color() in paintInterface() since this turns out to be an expensive call.
* Don't initialize the view options in paintInterface() if we don't need to paint any icons.