Made the number of threads a command-line parameter again.

I have restored the -t command-line parameter and removed the parameter from all the yaml files. I have also updated the run.sh scripts with a default value of 16.

That fixes #144 (closed) and the branch can be removed if you are happy with the changes. Thanks !

mentioned in merge request !143 (merged)

Status changed to merged

mentioned in commit 622ad2b6

Seems to work, so accepting.