Feature: Per-group wagon removal flag.

src/autoreplace_cmd.cpp

@@ -741,6 +741,9 @@ CommandCost CmdAutoreplaceVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1
 	const Company *c = Company::Get(_current_company);
 	bool wagon_removal = c->settings.renew_keep_length;
 
+	const Group *g = Group::GetIfValid(v->group_id);
+	if (g != nullptr) wagon_removal = HasBit(g->flags, GroupFlags::GF_REPLACE_WAGON_REMOVAL);
+
 	/* Test whether any replacement is set, before issuing a whole lot of commands that would end in nothing changed */
 	Vehicle *w = v;
 	bool any_replacements = false;