Support RPG::Terms 0x3 defaulting semantics

RPG::Terms 0x3 if empty string will be present in a 2k database
but not a 2k3 database. This appears a one-off situation so it
is hacked in for now..

src/reader_struct.cpp

@@ -110,7 +110,7 @@ void Struct<S>::WriteLcf(const S& obj, LcfWriter& stream) {
 					  << " after " << last
 					  << " in struct " << name
 					  << std::endl;
-		if (!field->present_if_default && field->IsDefault(obj, ref)) {
+		if (!field->isPresentIfDefault(db_is2k3) && field->IsDefault(obj, ref)) {
 			continue;
 		}
 		stream.WriteInt(field->id);
@@ -135,7 +135,7 @@ int Struct<S>::LcfSize(const S& obj, LcfWriter& stream) {
 			continue;
 		}
 		//printf("%s\n", field->name);
-		if (!field->present_if_default && field->IsDefault(obj, ref)) {
+		if (!field->isPresentIfDefault(db_is2k3) && field->IsDefault(obj, ref)) {
 			continue;
 		}
 		result += LcfReader::IntSize(field->id);

src/reader_struct.h

@@ -32,6 +32,7 @@
 #include "rpg_treemap.h"
 #include "rpg_rect.h"
 #include "rpg_savepicture.h"
+#include "rpg_terms.h"
 
 // Forward declarations
 
@@ -304,6 +305,15 @@ struct Field {
 	virtual void BeginXml(S& obj, XmlReader& stream) const = 0;
 	virtual void ParseXml(S& obj, const std::string& data) const = 0;
 
+	bool isPresentIfDefault(bool db_is2k3) const {
+		if (std::is_same<S,RPG::Terms>::value && db_is2k3 && id == 0x3) {
+			//Special case - only known field that is 2k specific and not
+			//written to a 2k3 db if defaulted.
+			return false;
+		}
+		return present_if_default;
+	}
+
 	Field(int id, const char* name, bool present_if_default, bool is2k3) :
 		name(name), id(id), present_if_default(present_if_default), is2k3(is2k3) {}
 };