Supporting UNIX sockets in address matching.

This closes #645 issue on GitHub.

(Also moved a changelog line that was misplaced in a previous commit.)

docs/changes.xml

@@ -31,6 +31,12 @@ NGINX Unit updated to 1.28.0.
          date="" time=""
          packager="Nginx Packaging <nginx-packaging@f5.com>">
 
+<change type="feature">
+<para>
+supporting UNIX sockets in address matching.
+</para>
+</change>
+
 <change type="feature">
 <para>
 forwarded header to replace client address and protocol.
@@ -49,6 +55,12 @@ more http variables support.
 </para>
 </change>
 
+<change type="feature">
+<para>
+added a new variable, $dollar, that translates to a literal "$" during
+</para>
+</change>
+
 <change type="bugfix">
 <para>
 an index file that didn't contain a file extension was incorrectly
@@ -62,13 +74,6 @@ increased the applications' startup timeout.
 </para>
 </change>
 
-<change type="feature">
-<para>
-added a new variable, $dollar, that translates to a literal "$" during
-variable substitution.
-</para>
-</change>
-
 </changes>