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.
4637. [func] "nsec3hash -r" option ("rdata order") takes arguments
in the same order as they appear in NSEC3 or
NSEC3PARAM records, so that NSEC3 parameters can
be cut and pasted from an existing record. Thanks
to Tony Finch for the contribution. [RT #45183]