more fixes & polish on the release script
 - fixed zip_pack to include subdirectories too
 - also unpack & run functional tests from the -src archive
 - print output on error in call()
 - ask whether or not to test the bundles before building everything so that I can go grab something to drink :)
fixed individuals/s/period computation when a simulation (namely variant.yml) runs in 0.0s so that it does not raise an exception :)