The ANS servers were not to written to handle NS queries at the
QNAME resulting in gratuitious protocol errors that will break tests
when NS requests are made for the QNAME.
CookieOption with new .server/.client attributes (rather than .data) was
added to dnspython. Adjust the code to use the new attributes if
available and fall back to the old code for dnspython<2.7.0
compatibility.
This commit converts the license handling to adhere to the REUSE
specification. It specifically:
1. Adds used licnses to LICENSES/ directory
2. Add "isc" template for adding the copyright boilerplate
3. Changes all source files to include copyright and SPDX license
header, this includes all the C sources, documentation, zone files,
configuration files. There are notes in the doc/dev/copyrights file
on how to add correct headers to the new files.
4. Handle the rest that can't be modified via .reuse/dep5 file. The
binary (or otherwise unmodifiable) files could have license places
next to them in <foo>.license file, but this would lead to cluttered
repository and most of the files handled in the .reuse/dep5 file are
system test files.
