Bug 167545 Copy a cascading parameter group and paste it to another parameter group causes an exception thrown
Steps to reproduce: 1.Copy a cascading parameter group using short cut key "Ctrl+x"/"Ctrl+c", or choosing context menu "Cut"/"Copy"; 2.Paste it to another parameter group using short cut key "Ctrl+v", or choosing context menu "Paste"; Expected result: The source one is pasted in the destination. Actual result: An exception thrown org.eclipse.birt.report.model.api.command.ContentException: The Cascading Parameter Group("Source") is not allowed in the slot (parameters) of Parameter Group("Destination").
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
{
			DimensionHandle dimension = (DimensionHandle) object;
			measure = dimension.getMeasure( );
			units = dimension.getUnits( );
		}
		if ( DesignChoiceConstants.UNITS_PX.equals( units ) )
		{
			return measure;
		}
		
		if ( "".equalsIgnoreCase( units ) ) 
		{
			px = measure;
		}
		if ( fontSize == 0 )
		{
			Font defaultFont = JFaceResources.getDefaultFont( );
			FontData[] fontData = defaultFont.getFontData( );
			fontSize = fontData[0].getHeight( );
		}
		if ( DesignChoiceConstants.UNITS_EM.equals( units ) )
		{
			px = DimensionUtil.convertTo( measure * fontSize,
					DesignChoiceConstants.UNITS_PT,
					DesignChoiceConstants.UNITS_IN ).getMeasure( );
		}
		else if ( DesignChoiceConstants.UNITS_EX.equals( units ) )
		{
			px = DimensionUtil.convertTo( measure * fontSize / 3,
					DesignChoiceConstants.UNITS_PT,