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
private void dropEmbeddedImageHandle( EmbeddedImageHandle embeddedImage )
	{
		embeddedImageList.add( embeddedImage );
	}
	protected void dropSourceElementHandle( DesignElementHandle handle )
			throws SemanticException
	{
		if ( handle.getContainer( ) != null )
		{
			if ( DesignerConstants.TRACING_COMMANDS )
			{
				System.out.println( "DeleteCommand >> Dropping " 
						+ DEUtil.getDisplayLabel( handle ) );
			}
			if ( handle instanceof CellHandle )
			{
				dropSourceSlotHandle( ( (CellHandle) handle ).getContent( ) );
			}
			else if ( handle instanceof RowHandle )
			{
				new DeleteRowCommand( handle ).execute( );
			}
			else if ( handle instanceof ColumnHandle )
			{
				new DeleteColumnCommand( handle ).execute( );
			}
			else
			{
				handle.drop( );
			}