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
* 
	 * @param name
	 *            Name of the style to find.
	 * @return The style, or null if the style is not found.
	 */
	public StyleElement findStyle( String name )
	{
		ElementRefValue refValue = moduleNameSpaces[STYLE_NAME_SPACE]
				.resolve( name );
		return (StyleElement) refValue.getElement( );
	}
	/**
	 * Finds a named report item in this module and the included modules. This
	 * is for body elements in the element's name space.
	 * 
	 * @param name
	 *            The name of the element to find.
	 * @return The element, or null if the element is not found.
	 */
	public DesignElement findElement( String name )
	{
		return resolveNativeElement( name, ELEMENT_NAME_SPACE );
	}
	/**
	 * Finds DataSet/DataSource in the self or included libraries. The name is
	 * the full path for included libraries. For example, it can be one of
	 * followings:
	 * 
	 * <ul>
	 * <li>lib1.lib2.dataSet1