Wikied: Pseudo-Listbox

[Rackle]

Implement a pseudo multi-column listbox such that each "cell" of a row can contain any widget.

An improvement would be to design a single row and clone this "template" row to multiple times. This would make it easier to design a .layout such that each row is identical; same widget width, height, and distance between two widgets, as well as same distance between two rows.