Bug 155958 Backward compatibility on 'resultset' property
Before 2.0 build, we always take the 'resultset' property on as resultset hint function. But currently, it is different.'resultset' property is to keep the oda resultset metadata,'resultsetHints' replace the function of 'resultset' as the real hints property. Currently Model has done backward compatibility on transform between 'resultset' and 'resultsetHints' by copying 'resultset' to 'resultsetHints', but 'resultset''s value still exist, it will break the current impl when fetching this property, because now we have taken this property to save the metadata of Oda resultset not hints info. To make old report design working fine, we should clear 'resultset' property, then we can use it as real resultset property.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/parser/OdaDataSetState.java
* The provider of the element.
	 */
	private ODAProvider provider = null;
	/**
	 * Constructs the oda data set with the design file parser handler.
	 * 
	 * @param handler
	 *            the design file parser handler
	 */
	public OdaDataSetState( ModuleParserHandler handler )
	{
		super( handler );
		element = new OdaDataSet( );
	}
	/**
	 * Constructs the data set state with the design parser handler, the
	 * container element and the container slot of the data set.
	 * 
	 * @param handler
	 *            the design file parser handler
	 * @param theContainer
	 *            the element that contains this one
	 * @param slot
	 *            the slot in which this element appears
	 */
	public OdaDataSetState( ModuleParserHandler handler,
			DesignElement theContainer, int slot )
	{
		super( handler, theContainer, slot );
		element = new OdaDataSet( );