Bug 121498 When datasource/dataset deleted, the datasource/dataset property binding element haven't been deleted
When deleted the datasource/dataset, the datasource/dataset property binding element haven't been deleted. Expected result: This operation must be a transaction.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/DesignElementHandle.java
* element does not have a name. Many elements do not require a name. The
	 * name does not inherit. If this element does not have a name, it will not
	 * inherit the name of its parent element.
	 * 
	 * @return the element name, or null if the name is not set
	 */
	public String getName( )
	{
		return getElement( ).getName( );
	}
	/**
	 * Gets the name of this element. The returned element name will be the same
	 * as <CODE>getName()</CODE>, plus the namespace of the module that the
	 * elment is contained, if any. If the element is existed in the current
	 * module,this method and <CODE>getName()</CODE> will return identical
	 * results.
	 * 
	 * @return the qualified name of thie element.
	 */
	public String getQualifiedName( )
	{
		if ( getElement( ).getName( ) == null )
			return null;
		Module rootElement = getElement( ).getRoot( );
		if ( rootElement instanceof Library )
		{
			String namespace = ( (Library) rootElement ).getNamespace( );
			return StringUtil.buildQualifiedReference( namespace, getElement( )
					.getName( ) );
		}