Add new changelog file

Create new changelog and include it in the documentation. Include the
previous CHANGES as plain text without any markup.

(cherry picked from commit e9b6031e0c)

CHANGES

@@ -0,0 +1 @@
+doc/arm/changelog.rst

NEWS

@@ -1 +1 @@
-CHANGES
+doc/arm/changelog.rst

doc/arm/Makefile.am

@@ -5,6 +5,7 @@ EXTRA_DIST =					\
 	advanced.inc.rst			\
 	build.inc.rst				\
 	catz.inc.rst				\
+	changelog.rst				\
 	chapter10.rst				\
 	chapter1.rst				\
 	chapter2.rst				\

doc/arm/index.rst

@@ -37,6 +37,7 @@ BIND 9 Administrator Reference Manual
    :maxdepth: 2
 
    notes
+   changelog
    dnssec-guide
    history
    general

doc/arm/notes.rst

@@ -9,6 +9,8 @@
 .. See the COPYRIGHT file distributed with this work for additional
 .. information regarding copyright ownership.
 
+.. _relnotes:
+
 Release Notes
 =============
 
@@ -19,7 +21,8 @@ Introduction
 
 BIND 9.18 (Extended Support Version) is a stable branch of BIND. This
 document summarizes significant changes since the last production
-release on that branch.
+release on that branch. Please see the :ref:`changelog` file for
+a more detailed list of changes and bug fixes.
 
 Supported Platforms
 -------------------