this restores functionality that was removed in commit 03be5a6b4e,
allowing named to search in authoritative zone databases outside the
current zone for additional data, if and only if recursion is allowed
and minimal-responses is disabled.
- all tests with "recursion yes" now also specify "dnssec-validation yes",
and all tests with "recursion no" also specify "dnssec-validation no".
this must be maintained in all new tests, or else validation will fail
when we use local root zones for testing.
- clean.sh has been modified where necessary to remove managed-keys.bind
and viewname.mkeys files.
- 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
