The reason is simple.  When I check for docker-compose, the
execution can fail.  Then I'll check for the built-in
docker compose.  If set -e is active the first failure will result
the script being aborted with no chance to check for the second
option.

Instead do it in the function itself in order to make it more
visible what is actually done.

The bash -e shebang does not work on CentOS 7.

The script can now locate itself and set LOFAR20_DIR accordingly.
This allows for multiple installations in parallel.

- Replace the set +e/set -e with || true when loading the Tango DB.
- Explain why in the world I am starting dsconfig twice.

L2SS-218 Addressing the comment that this file could be sourced when ssh'ing into the computer and it would break ssh when printing something that is unexpected.

This allows make to return with a non-0 code which in turn does
not force Bash to exit.  This happens when the containers where
already down and/or the volumes cleaned up.