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
* @param propName
	 *            the property name
	 * @param value
	 *            the value to set
	 * @throws SemanticException
	 *             if the property value cannot be converted from a number.
	 */
	public void setNumberProperty( String propName, BigDecimal value )
			throws SemanticException
	{
		setProperty( propName, value );
	}
	/**
	 * Clears the value of a property. Clearing a property removes any value set
	 * for the property on this element. After this, the element will now
	 * inherit the property from its parent element, style, or from the default
	 * value for the property.
	 * 
	 * @param propName
	 *            the name of the property to clear.
	 * @throws SemanticException
	 *             if the property is not defined on this element
	 */
	public void clearProperty( String propName ) throws SemanticException
	{
		setProperty( propName, null );
	}
	/**
	 * Clears values of all properties. Clearing a property removes any value
	 * set for the property on this element. After this, the element will now