Add a workaround for those who want to use different versions of the ant plugin.

git-svn-id: https://svn.apache.org/repos/asf/maven/maven-1/plugins/trunk@405231 13f79535-47bb-0310-9956-ffa450edef68

ant/xdocs/properties.xml

@@ -108,5 +108,12 @@
         </tr>
       </table>
     </section>
+    <section name="Backward compatibility">
+      <p>In the version 1.10 of the ant plugin we removed the usage of the property "maven.ant.generatebuild.file" to replace it by the properties "maven.ant.generate.dir" and "maven.ant.generate.script".</p>
+      <p>If you used this property (for example you had : <code>maven.ant.generatebuild.file=myDir/myBuild.xml</code>) and you want to have a build which work with all the versions of this plugin you can set your properties like this :</p>
+      <source>maven.ant.generatebuild.file=${maven.ant.generate.dir}/${maven.ant.generate.script}
+maven.ant.generate.dir=myDir
+maven.ant.generate.script=myBuild.xml</source>
+    </section>
   </body>
 </document>