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/core/Module.java
* <li>lib1.dataSource1
	 * </ul>
	 * 
	 * @param name
	 *            the element name in full path.
	 * @param namespaceId
	 *            the name space id
	 * @return the element that matches <code>name</code>.
	 */
	protected DesignElement findElementInLibraries( String name, int namespaceId )
	{
		String namespace = StringUtil.extractNamespace( name );
		String elementName = StringUtil.extractName( name );
		if ( namespace == null )
			return resolveNativeElement( elementName, namespaceId );
		Library lib = getVisibleLibraryWithNamespace( namespace );
		if ( lib == null )
			return null;
		return lib.findElementInLibraries( elementName, namespaceId );
	}
	/**
	 * Finds a data source by name in this module and the included modules.
	 * 
	 * @param name
	 *            the name of the data source to find.
	 * @return the data source, or null if the data source is not found.
	 */
	public DesignElement findDataSource( String name )
	{
		return findElementInLibraries( name, DATA_SOURCE_NAME_SPACE );