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/metadata/ElementPropertyDefn.java
implements
			IElementPropertyDefn
{
	/**
	 * The proposal is to extend the extension schema to allow extended items to
	 * override some predefined properties such as "onRender".
	 */
	protected boolean useOwnModel = false;
	/**
	 * The message ID for the property group name.
	 */
	protected String groupNameKey = null;
	/**
	 * <code>true</code> if the value of the property can be inherited,
	 * <code>false</code> if not.
	 */
	protected boolean isInheritable = true;
	/**
	 * Default constructor.
	 */
	public ElementPropertyDefn( )
	{
	}
	/**
	 * Returns the group name (if any) for the property.
	 *