ADDED: pad fabrication property, as required in latest Gerber file specification.

Property is a pad info used mainly for fabrication or test.
Currently, supported properties are:
BGA property (variant of SMD pad)
Fiducial (global to the board or local to the footprint)
Test Point
Heat sink
Castellated.
And are used in Gerber files (copper layers and drill files)

Increment BOARD_FILE_VERSION  to 20200104

pcbnew/plot_brditems_plotter.cpp

@@ -142,12 +142,38 @@ void BRDITEMS_PLOTTER::PlotPad( D_PAD* aPad, COLOR4D aColor, EDA_DRAW_MODE_T aPl
                 break;
 
             case PAD_ATTRIB_SMD:       // SMD pads (One external copper layer only) with solder paste
-                // If round shape, perhaps a BGA pad but not sure: so use currently SMDPAD attribute,
-                // until an explicit BGA pad attribute is added in Pcbnew
-//                if( aPad->GetShape() == PAD_SHAPE_CIRCLE )
-//                    gbr_metadata.SetApertureAttrib( GBR_APERTURE_METADATA::GBR_APERTURE_ATTRIB_BGAPAD_CUDEF );
-//                else
-                    gbr_metadata.SetApertureAttrib( GBR_APERTURE_METADATA::GBR_APERTURE_ATTRIB_SMDPAD_CUDEF );
+                gbr_metadata.SetApertureAttrib( GBR_APERTURE_METADATA::GBR_APERTURE_ATTRIB_SMDPAD_CUDEF );
+                break;
+            }
+
+            // Fabrication properties can have specific GBR_APERTURE_METADATA options:
+            switch( aPad->GetProperty() )
+            {
+            case PAD_PROP_BGA:
+                gbr_metadata.SetApertureAttrib( GBR_APERTURE_METADATA::GBR_APERTURE_ATTRIB_BGAPAD_CUDEF );
+                break;
+
+            case PAD_PROP_FIDUCIAL_GLBL:
+                gbr_metadata.SetApertureAttrib( GBR_APERTURE_METADATA::GBR_APERTURE_ATTRIB_FIDUCIAL_GLBL );
+                break;
+
+            case PAD_PROP_FIDUCIAL_LOCAL:
+                gbr_metadata.SetApertureAttrib( GBR_APERTURE_METADATA::GBR_APERTURE_ATTRIB_FIDUCIAL_LOCAL );
+                break;
+
+            case PAD_PROP_TESTPOINT:    // Only on outer layers
+                gbr_metadata.SetApertureAttrib( GBR_APERTURE_METADATA::GBR_APERTURE_ATTRIB_TESTPOINT );
+                break;
+
+            case PAD_PROP_HEATSINK:
+                gbr_metadata.SetApertureAttrib( GBR_APERTURE_METADATA::GBR_APERTURE_ATTRIB_HEATSINKPAD );
+                break;
+
+            case PAD_PROP_CASTELLATED:
+                gbr_metadata.SetApertureAttrib( GBR_APERTURE_METADATA::GBR_APERTURE_ATTRIB_CASTELLATEDPAD );
+                break;
+
+            case PAD_PROP_NONE:
                 break;
             }
         }