add removeAttribute method to Xpp3Dom (#94)

* add removeAttribute method to Xpp3Dom

Signed-off-by: olivier lamy <olamy@apache.org>

* add javadoc

Signed-off-by: olivier lamy <olamy@apache.org>

src/main/java/org/codehaus/plexus/util/xml/Xpp3Dom.java

@@ -16,6 +16,7 @@
  * limitations under the License.
  */
 
+import org.codehaus.plexus.util.StringUtils;
 import org.codehaus.plexus.util.xml.pull.XmlSerializer;
 
 import java.io.IOException;
@@ -183,6 +184,17 @@ public String getAttribute( String name )
         return ( null != attributes ) ? attributes.get( name ) : null;
     }
 
+    /**
+     *
+     * @param name name of the attribute to be removed
+     * @return <code>true</code> if the attribute has been removed
+     * @since 3.4.0
+     */
+    public boolean removeAttribute( String name )
+    {
+        return StringUtils.isEmpty( name ) ? false: attributes.remove( name ) == null;
+    }
+
     /**
      * Set the attribute value
      *