[Oberon] Oberon system building tools (including Oberon0.Mod)

[Andreas Pirklbauer]

> This of course depends on Elements being available,
> which in turn implies that Clemens Szyperski's design
> has been implemented. It is the case under both V4
> and S3, but probably not under EO or Wirth's
> System 5. These two latter Systems will have
> to rely on the Traditional Oberon Mouse (TOM).

It would make for a nice student exercise to add
Elements to EO or V5 (with or without keeping
the system backward-compatible).