[rt46602] Miscellaneous changes to existing parallelised tests

[rt46602] Miscellaneous changes to existing parallelised tests

Currently these tests are allow_query, rpzrecurse and serve-stale

1. Function to copy files and set port numbers renamed from copy_config
to copy_setports, as this is used to change the ports in Perl and Python
test scripts as well.
2. Changes to rpzrecurse/tests.sh to handle two calls to getopts (one to
parse port numbers, the other to parse rpzrecurse-specific options). Also
fixed various commands to use correct ports.
3. Updates to "clean.sh" scripts to ensure that all files created in the
test are removed.