Noted windows-slaves-plugin split in 1.547

If it's significant enough to introduce regressions, it's significant enough for the changelog.

changelog.html

@@ -119,6 +119,8 @@ Upcoming changes</a>
 </ul>
 <h3><a name=v1.547>What's new in 1.547</a> (2014/01/12)</h3>
 <ul class=image>
+  <li class=rfe>
+    Split Windows slave functionality into its own plugin.
   <li class="major bug">
     NPE since 1.545 when using aggregated test result publisher without specifying downstream jobs explicitly.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-18410">issue 18410</a>)