The only difference is that functions are not individually listed by name,
but that seems completely pointless, since all functions that are documented
are always exported, so the generic text tells the user all she or he needs
to know.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
Also introduce sd_journal_has_runtime_files() and
sd_journal_has_persistent_files() to the public API. These functions
can be used to easily find out if the open journal files are runtime
and/or persistent.
