The lessons of looking around, laying, the curves, correcting a curve, joining, the switches, selecting and editing with
the gizmo each name a clip, lang/editor_tutorial/<name>.gif. The editor tutorial that #289 brings plays them, but doesn't
carry them: they were recorded on feat/switch-blades and stayed there. Taken from it as they are, 6.1 MB; the packages copy
lang/ whole, so they go out with the game. Without them a lesson just shows no clip.
