Bug 122850 Table/list should not be able to be inserted in Master Page mode.
Description: Table/list should not be able to be inserted in Master Page mode. Steps to reproduce: 1. New a report and transfer to Master Page mode. 2. New a datasource and dataset 3. Drag a list/table to page header/footer, bind it to dataset and drag some columns inside. 4. Save and preview Expected result: Insert list/table item in master page should be forbidden. Actual result: They are allowed and preview showed "undefine" in page
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/util/ModelUtil.java
DesignElement virtualChild = (DesignElement) clonedIter.next( );
			String name = virtualChild.getName( );
			virtualChild.clearAllProperties( );
			if ( name != null )
				virtualChild.setName( name );
			virtualChild.setBaseId( virtualParent.getID( ) );
		}
		
		for ( int i = 0; i < source.getDefn( ).getSlotCount( ); i++ )
		{
			ContainerSlot sourceSlot = cloned.getSlot( i );
			ContainerSlot targetSlot = target.getSlot( i );
			
			int count = targetSlot.getCount( );
			while ( --count >= 0 )
			{
				targetSlot.remove( count );
			}
			for ( int j = 0; j < sourceSlot.getCount( ); j++ )
			{
				DesignElement content = sourceSlot.getContent( j );
				
				targetSlot.add( content );
				content.setContainer( target, i );
			}
		}
		return true;
	}
	/**
	 * Break the relationship between the given element to its parent.Set all