Bug 188283 Bubbles should be z-sorted by size in Bubble charts
Biggest bubbles should be drawn first so that there is no small bubble hidden by a bigger one.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/render/DeferredCache.java
mi.getEvent( ).fill( idr );
						mi.getEvent( ).draw( idr );
						break;
					case PrimitiveRenderEvent.FILL :
						mi.getEvent( ).fill( idr );
						break;
					case PrimitiveRenderEvent.DRAW :
						mi.getEvent( ).draw( idr );
						break;
				}
			}
			alMarkers.clear( );
		}
		
		if ( ( options & FLUSH_LABLE ) == FLUSH_LABLE )
		{
			for ( int i = 0; i < alLabels.size( ); i++ )
			{
				TextRenderEvent tre = (TextRenderEvent) alLabels.get( i );
				tre.draw( idr );
			}
			alLabels.clear( );
		}
		
		if ( ( options & FLUSH_3D ) == FLUSH_3D )
		{
			for ( int i = 0; i < al3D.size( ); i++ )
			{
				Object obj = al3D.get( i );
				if ( obj instanceof WrappedInstruction )