scripts: Document private modules as such in a CHANGES section

This is to try to make sure, that even if documented, people will not
accidentally rely on private modules, that have not API stability
guarantees.

debian/changelog

@@ -26,6 +26,7 @@ dpkg (1.17.17) UNRELEASED; urgency=low
     - Mark Dpkg::BuildProfiles as a public module.
     - Document all public module versions in a CHANGES section.
     - Remove EXPORTED from POD section titles.
+    - Document private modules as such in a CHANGES section.
   * Set the DEB_TARGET_* dpkg-architecture variables from architecture.mk.
     Missed in dpkg 1.17.14.
   * Initialize DEB_TARGET_ARCH variable without requiring DEB_HOST_ARCH,

scripts/Dpkg/BuildEnv.pm

@@ -102,6 +102,12 @@ sub list_modified {
 
 =back
 
+=head1 CHANGES
+
+=head2 Version 0.xx
+
+This is a private module.
+
 =cut
 
 1;

scripts/Dpkg/Control/Types.pm

@@ -53,6 +53,12 @@ use constant {
     CTRL_CHANGELOG => 512,   # Output of dpkg-parsechangelog
 };
 
+=head1 CHANGES
+
+=head2 Version 0.xx
+
+This is a private module.
+
 =head1 AUTHOR
 
 Raphaël Hertzog <hertzog@debian.org>.

scripts/Dpkg/Vendor/Debian.pm

@@ -293,4 +293,12 @@ sub _add_hardening_flags {
     }
 }
 
+=head1 CHANGES
+
+=head2 Version 0.xx
+
+This is a private module.
+
+=cut
+
 1;

scripts/Dpkg/Vendor/Default.pm

@@ -131,6 +131,12 @@ sub run_hook {
 
 =back
 
+=head1 CHANGES
+
+=head2 Version 0.xx
+
+This is a private module.
+
 =cut
 
 1;

scripts/Dpkg/Vendor/Ubuntu.pm

@@ -181,6 +181,12 @@ sub find_launchpad_closes {
 
 =back
 
+=head1 CHANGES
+
+=head2 Version 0.xx
+
+This is a semi-private module. Only documented functions are public.
+
 =cut
 
 1;