[Oberon] minor tuning of TUI?

[Richard Hable]

Am 2016-06-13 um 20:56 schrieb Aubrey.McIntosh at alumni.utexas.net:

> Everything in V4 had a safety net built in.  If you closed the last
> viewer, you had the System.Restore (or some such) command to open the
> last closed viewer.

That would help, if there was some warning message after closing the
last viewer, reminding you to reopen the viewer in time before closing
other viewers. The same goes for accidently overwriting files: if you
don't immediately find out for yourself that you made a mistake, you
lose data.

Richard