Allow customizing of MANIFEST.MF.

Add test cases for the customization


git-svn-id: https://svn.apache.org/repos/asf/maven/maven-1/plugins/trunk@114957 13f79535-47bb-0310-9956-ffa450edef68

war/xdocs/properties.xml

@@ -112,6 +112,14 @@
               <code>${maven.war.build.dir}/${pom.artifactId}</code>.
           </td>
         </tr>
+        <tr>
+          <td>maven.war.manifest</td>
+          <td>Yes</td>
+          <td>
+			Location of the MANIFEST.MF file in the source tree. It defaults to 
+			<code>${pom.build.sourceDirectory}/META-INF/MANIFEST.MF</code>.
+          </td>
+        </tr>
         <tr>
           <td>maven.war.index</td>
           <td>Yes</td>