[Oberon] First stable release v1.0 of Extended Oberon available

[Andreas Pirklbauer]

    > I now have to check what it takes to get THM-Oberon up-to-date :-)

A one time exercise. Unfortunately, I don’t know which experimental 
version you were basing your work on in the past. A ‘diff' should help.

But from now on, old releases won’t be removed and there will
be documented upgrade paths to future releases, if necessary.

For example, when Extended Oberon becomes available on RISC-V..