re-add duc importing for new savefile system

desmume/src/NDSSystem.cpp

@@ -1090,7 +1090,7 @@ int NDS_ImportSave(const char *filename)
 		return 0;
 
 	if (memcmp(filename+strlen(filename)-4, ".duc", 4) == 0)
-		return mc_load_duc(&MMU.bupmem, filename);
+		return MMU_new.backupDevice.load_duc(filename);
 
 	return 0;
 }

desmume/src/mc.cpp

@@ -874,3 +874,39 @@ void BackupDevice::flush()
 		LOG("Unable to open savefile %s\n",filename.c_str());
 	}
 }
+
+bool BackupDevice::load_duc(const char* filename)
+{
+  long size;
+   char id[16];
+   FILE* file = fopen(filename, "rb");
+   size_t elems_read = 0;
+   if(file == NULL)
+      return false;
+
+   fseek(file, 0, SEEK_END);
+   size = ftell(file) - 500;
+   fseek(file, 0, SEEK_SET);
+
+   // Make sure we really have the right file
+   elems_read += fread((void *)id, sizeof(char), 16, file);
+
+   if (memcmp(id, "ARDS000000000001", 16) != 0)
+   {
+	   LOG("Not recognized as a valid DUC file\n");
+      fclose(file);
+      return false;
+   }
+   // Skip the rest of the header since we don't need it
+   fseek(file, 500, SEEK_SET);
+
+   ensure((u32)size);
+
+   fread(&data[0],1,size,file);
+   fclose(file);
+
+   flush();
+
+   return true;
+
+}

desmume/src/mc.h

@@ -88,6 +88,8 @@ public:
 	static u32 addr_size_for_old_save_size(int bupmem_size);
 	static u32 addr_size_for_old_save_type(int bupmem_type);
 
+	bool load_duc(const char* filename);
+
 private:
 	BOOL write_enable;	//is write enabled?
 	u32 com;	//persistent command actually handled