Bug 182076 Delete a style from a report item doesn't affect report xml source
Steps to reproduce: 1.Insert a label onto layout; 2.New a style, suppose named it "NewStyle"; 3.Right click the label and on the drop down list, choose Style->Apply Style->NewStyle; 4.Save the report design; 5.Right click the label and on the drop down list, choose Style->Delete Style->NewStyle; 6.Save the report design; Expected result: NewStyle is deleted from report design, and the label doesn't have the style property. Actual result: Switch to report xml source, a error mark indicate that the label still has a style property:<property name="style">NewStyle</property>
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/core/commands/DeleteCommand.java
}
	}
	protected void dropSourceSlotHandle( SlotHandle slot )
			throws SemanticException
	{
		if ( DesignerConstants.TRACING_COMMANDS )
		{
			System.out.println( "DeleteCommand >> Dropping slot " 
					+ slot.getSlotID( )
					+ " of " 
					+ DEUtil.getDisplayLabel( slot.getElementHandle( ) ) );
		}
		List list = slot.getContents( );
		for ( int i = 0; i < list.size( ); i++ )
		{
			dropSourceElementHandle( (DesignElementHandle) list.get( i ) );
		}
	}
	protected void dropCssStyleHandle( CssStyleSheetHandle cssStyleHandle )
			throws SemanticException
	{
		if ( DesignerConstants.TRACING_COMMANDS )
		{
			System.out.println( "DeleteCommand >> Dropping " 
					+ DEUtil.getDisplayLabel( cssStyleHandle.getElementHandle( ) ) );
		}
		DesignElementHandle containerHandle = cssStyleHandle.getContainerHandle( );
		if(containerHandle instanceof ReportDesignHandle)
		{
			ReportDesignHandle report = (ReportDesignHandle)containerHandle;