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
return getElement( ).getFloatProperty( module, propName );
	}
	/**
	 * Returns the value of a property as a number (BigDecimal).
	 * 
	 * @param propName
	 *            the name of the property.
	 * @return the value as a number. Returns <code>null</code> if the value
	 *         cannot be converted to a number.
	 */
	public BigDecimal getNumberProperty( String propName )
	{
		return getElement( ).getNumberProperty( module, propName );
	}
	/**
	 * Returns a handle to work with a Dimension property. Returns null if the
	 * given property is not defined or not dimension property.
	 * 
	 * @param propName
	 *            name of the property.
	 * @return a corresponding DimensionHandle to deal with the dimension
	 *         property. Return <code>null</code> if the property is defined
	 *         or not dimension property.
	 * 
	 * @see DimensionHandle
	 */
	public DimensionHandle getDimensionProperty( String propName )
	{
		ElementPropertyDefn propDefn = getElement( ).getPropertyDefn( propName );
		if ( propDefn == null )