Restore unreleased binary compatibility change

- Remove old comment

Author: garydgregory

pom.xml

@@ -139,13 +139,6 @@
                 <tarLongFileMode>gnu</tarLongFileMode>
             </configuration>
         </plugin>
-	<!-- Disabled as it is not Java 6 compatible
-      <plugin>
-        <groupId>com.github.siom79.japicmp</groupId>
-        <artifactId>japicmp-maven-plugin</artifactId>
-        <version>${commons.japicmp.version}</version>
-      </plugin>
-      -->
       </plugins>
       <pluginManagement>
         <plugins>

src/main/java/org/apache/commons/beanutils/ConversionException.java

@@ -27,6 +27,13 @@ public class ConversionException extends RuntimeException {
 
     private static final long serialVersionUID = 1L;
 
+    /**
+     * The cause, deprecated.
+     *
+     * @deprecated Use {@link Throwable#getCause()}}.
+     */
+    protected Throwable cause;
+    
     /**
      * Constructs a new exception with the specified message.
      *
@@ -44,6 +51,7 @@ public ConversionException(final String message) {
      */
     public ConversionException(final String message, final Throwable cause) {
         super(message, cause);
+        this.cause = cause;
     }
 
     /**
@@ -53,6 +61,7 @@ public ConversionException(final String message, final Throwable cause) {
      */
     public ConversionException(final Throwable cause) {
         super(cause);
+        this.cause = cause;
     }
 
 }