Bug 145698 Name change won't enable "restore property" button
Steps to reproduce: 1.New a report, extends lib.label 2.Choose the label, switch to property editor, chang its name to "aa" 3.Choose the label again Expected result: "Restore property" button is enabled Actual result: "Restore property" button is grayed out
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ModuleHandle.java
{
		PropertyHandle propHandle = this.getPropertyHandle( IMAGES_PROP );
		int pos = findImagePos( name );
		if ( pos < 0 )
			throw new PropertyValueException( getElement( ), propHandle
					.getPropertyDefn( ), name,
					PropertyValueException.DESIGN_EXCEPTION_ITEM_NOT_FOUND );
		propHandle.removeItem( pos );
	}
	/**
	 * Drops a translation from the design.
	 * 
	 * @param resourceKey
	 *            resource key of the message in which this translation saves.
	 * @param locale
	 *            the string value of the locale for a translation. Locale
	 *            should be in java-defined format( en, en-US, zh_CN, etc.)
	 * @throws CustomMsgException
	 *             if <code>resourceKey</code> is <code>null</code>.
	 * @see #getTranslation(String, String)
	 */
	public void dropTranslation( String resourceKey, String locale )
			throws CustomMsgException
	{
		CustomMsgCommand command = new CustomMsgCommand( getModule( ) );
		command.dropTranslation( resourceKey, locale );
	}
	/**
	 * Finds the position of the config variable with the given name.
	 *