Bug 213680 [2.2.2]Chart script can not be cleaned completely.
Description: Reset script or delete all script does not work. build version: v20071221-0630 steps to reproduce: 1. New a report. 2. New a chart. 3. Enter some script for the chart and save the report. 4. Click the reset scirpt button or delete all script. 5. Save the report and switch to layout,then switch back to script page. Expected result: Script are cleaned. Actual result: Script are not cleaned. Note: If you delete part of the script, it works.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/elements/ExtendedItem.java
* The extensibility provider which provides the functionality of this
	 * extensible element.
	 */
	protected PeerExtensibilityProvider provider = null;
	/**
	 * The methods for the extension element.
	 */
	private List methods = null;
	/**
	 * PropertDefinitions of the extension element.
	 */
	private List props = null;
	/**
	 * Default constructor.
	 */
	public ExtendedItem( )
	{
		provider = new DummyPeerExtensibilityProvider( this, null );
	}
	/**
	 * Constructs the extended item with an optional name.
	 * 
	 * @param theName
	 *            optional item name
	 */
	public ExtendedItem( String theName )
	{
		super( theName );
		provider = new DummyPeerExtensibilityProvider( this, null );
	}