message: gltfpack: Convert a few forgotten += to append()
  Consistency is important!
diff: @@ -1205,7 +1205,7 @@ void writeMaterialInfo(std::string& json, const cgltf_data* data, const cgltf_ma
  {
  comma(json);
  append(json, "\"alphaMode\":");
  - json += (material.alpha_mode == cgltf_alpha_mode_blend) ? "\"BLEND\"" : "\"MASK\"";
  + append(json, (material.alpha_mode == cgltf_alpha_mode_blend) ? "\"BLEND\"" : "\"MASK\"");
  }
  if (material.alpha_cutoff != 0.5f)
  @@ -1352,7 +1352,7 @@ void writeBufferView(std::string& json, BufferView::Kind kind, size_t count, siz
  if (kind == BufferView::Kind_Vertex || kind == BufferView::Kind_Index)
  {
  append(json, ",\"target\":");
  - json += (kind == BufferView::Kind_Vertex) ? "34962" : "34963";
  + append(json, (kind == BufferView::Kind_Vertex) ? "34962" : "34963");
  }
  if (compressed)
  {
  @@ -1374,11 +1374,11 @@ void writeAccessor(std::string& json, size_t view, size_t offset, cgltf_type typ
  append(json, ",\"byteOffset\":");
  append(json, offset);
  append(json, ",\"componentType\":");
  - json += componentType(component_type);
  + append(json, componentType(component_type));
  append(json, ",\"count\":");
  append(json, count);
  append(json, ",\"type\":");
  - json += shapeType(type);
  + append(json, shapeType(type));
  if (normalized)
  {
  @@ -1798,7 +1798,7 @@ void writeEmbeddedImage(std::string& json, std::vector<BufferView>& views, const
  append(json, "\"bufferView\":");
  append(json, view);
  append(json, ",\"mimeType\":\"");
  - json += mime_type;
  + append(json, mime_type);
  append(json, "\"");
  }
  @@ -1906,7 +1906,7 @@ bool process(cgltf_data* data, std::vector<Mesh>& meshes, const Settings& settin
  else
  {
  append(json_images, "\"uri\":\"");
  - json_images += image.uri;
  + append(json_images, image.uri);
  append(json_images, "\"");
  }
  }
  