WIP until we have a firm decision that this is the way to go... some Swing dialogues show the cancel button at the end (e.g.JFileChooser) and others (e.g.JOptionPane) at the start... (Linux here, since that might matter).

According to:https://ux.stackexchange.com/a/1077 placement is platform dependent, so I think we have to trust Swing to place them appropriately for system dialogs (file choosers etc). For ZAP dialogs we'd have to either pick an order and stick with it or check the platform and adapt (which seems overly complicated)...