Properly template the port number in config files with copy_setports.
The test takes two minutes on my machine which doesn't seem like a
proper justification to exclude it from the test suite, especially
considering we run these tests in parallel nowadays. The resource usage
doesn't seems significantly increased so it shouldn't interfere with
other system tests.
There also exists a precedent for longer running system tests that are
already part of the default system test suite (e.g. serve-stale takes
almost three minutes on the same machine).
The first step in all existing setup.sh scripts is to call clean.sh. To
reduce code duplication and ensure all system tests added in the future
behave consistently with existing ones, invoke clean.sh from run.sh
before calling setup.sh.
Temporary files created by a given system test should be removed by its
clean.sh script, not its setup.sh script. Remove redundant "rm"
invocations from setup.sh scripts. Move required "rm" invocations from
setup.sh scripts to their corresponding clean.sh scripts.
