this adds functions in conf.sh.common to create DS-style trust anchor
files. those functions are then used to create nearly all of the trust
anchors in the system tests.
there are a few exceptions:
- some tests in dnssec and mkeys rely on detection of unsupported
algorithms, which only works with key-style trust anchors, so those
are used for those tests in particular.
- the mirror test had a problem with the use of a CSK without a
SEP bit, which still needs addressing
in the future, some of these tests should be changed back to using
traditional trust anchors, so that both types will be exercised going
forward.
- add CHANGES note
- update copyrights and license headers
- add -j to the make commands in .gitlab-ci.yml to take
advantage of parallelization in the gitlab CI process
3943. [func] SERVFAIL responses can now be cached for a
limited time (configured by "servfail-ttl",
default 10 seconds, limit 30). This can reduce
the frequency of retries when an authoritative
server is known to be failing, e.g., due to
ongoing DNSSEC validation problems. [RT #21347]
