Pcbnew: prevent reversal of pad loading order when loading board.

When opening a board file and storing it again, the pads in all
embedded modules get reversed.  This is generally not really nice
if the PCB is managed by version control as it creates churn and
could make merges hard.

pcbnew/pcb_parser.cpp

@@ -1960,7 +1960,7 @@ MODULE* PCB_PARSER::parseMODULE_unchecked( wxArrayString* aInitialComments )
 
                 RotatePoint( &pt, module->GetOrientation() );
                 pad->SetPosition( pt + module->GetPosition() );
-                module->Add( pad );
+                module->Add( pad, ADD_APPEND );
             }
             break;