Until now all tests created their own temp directory.
If running from ./main this is different now.
The main script will create a tempdir and pass that as (hidden) command line
option to the test scripts - each will pick it up and create a subdir for
its experiment in there.
If a test is done and finishes succesfully it removes its own working
If, after all tests have run the temp directory is empty, it means that all
tests have finished succesfully and the temp directory is removed
So even after a fresh git clone the testing framework should
auto-init/update and "just run" ...
After a fresh git clone there won't be any binary correlator data yet but
the regression does run w/o blocking.
As errors occur, the artefacts (mostly logfiles only) will be left in /tmp