steal a paragraph from <fixcrlf>'s docs.

PR: 21658


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@274911 13f79535-47bb-0310-9956-ffa450edef68

docs/manual/CoreTasks/replace.html

@@ -13,6 +13,11 @@
 in selected file.</p>
 <p>If you want to replace a text that crosses line boundaries, you
 must use a nested <code>&lt;replacetoken&gt;</code> element.</p>
+
+<p>The output file is only written if it differs from the existing
+file.  This prevents spurious rebuilds based on unchanged files which
+have been regenerated by this task.</p> 
+
 <h3>Parameters</h3>
 <table border="1" cellpadding="2" cellspacing="0">
   <tr>
@@ -177,7 +182,7 @@ token]]&gt;&lt;/replacevalue&gt;
 <p><b>Note:</b> It is possible to use either the <i>token</i>/<code>&lt;replacetoken&gt;</code> and <i>value</i>/<code>&lt;replacevalue&gt;</code> attributes/elements, the nested replacefilter elements, or both in the same operation.
 </p>
 <hr>
-<p align="center">Copyright &copy; 2000-2002 Apache Software Foundation. All rights
+<p align="center">Copyright &copy; 2000-2003 Apache Software Foundation. All rights
 Reserved.</p>
 
 </body>

docs/manual/OptionalTasks/replaceregexp.html

@@ -13,6 +13,10 @@
 occurrence of a given regular expression with a substitution pattern
 in a selected file or set of files.</p>
 
+<p>The output file is only written if it differs from the existing
+file.  This prevents spurious rebuilds based on unchanged files which
+have been regenerated by this task.</p> 
+
 <p>Similar to <a href="../CoreTypes/mapper.html#regexp-mapper">regexp
 type mappers</a> this task needs a supporting regular expression
 library and an implementation of