Rename find_zone_keys() to dns__zone_findkeys() and move it to
lib/dns/zone_p.h, so that it can be used in unit tests. Add a comment
describing the purpose of this function.
(cherry picked from commit d7143986b1)
(cherry picked from commit fc0e99c7d7)
Rename update_sigs() to dns__zone_updatesigs() and move it to
lib/dns/zone_p.h, so that it can be unit tested. Add a comment
describing the purpose of this function.
(cherry picked from commit b1947cee82)
(cherry picked from commit 4d06f50ba8)
Rename zonediff_t to dns__zonediff_t and move it to lib/dns/zone_p.h, so
that unit tests can be written for functions taking pointers to
structures of this type as arguments.
(cherry picked from commit ace465a9f9)
(cherry picked from commit ea15c54d8a)
Add a new private header file, lib/dns/zone_p.h, which will hold type
definitions and function prototypes not meant to be exported by libdns,
but required by zone-related unit tests.
(cherry picked from commit c1bc3be806)
(cherry picked from commit 2b0add6d1a)
