serializer: improved robustness of project saving... maybe?

This seems to address a bug where sometimes QXmlStreamWriter would insert nonsense null characters into a project. This is probably some real edge case like compiler optimization or some bullshit like that. I don't even know if it affects all platforms, but it definitely affected me.

app/node/project/serializer/serializer.cpp

@@ -159,6 +159,11 @@ ProjectSerializer::Result ProjectSerializer::Save(const SaveData &data, const QS
 
     Result inner_result = Save(&writer, data, type);
 
+    if (writer.hasError()) {
+      Result r(kXmlError);
+      return r;
+    }
+
     project_file.close();
 
     if (inner_result != kSuccess) {
@@ -261,12 +266,8 @@ ProjectSerializer::Result ProjectSerializer::LoadWithSerializerVersion(uint vers
     LoadData ld = serializer->Load(project, reader, nullptr);
     Result r(kSuccess);
     if (reader->hasError()) {
-      qWarning() << "XML error:" << reader->errorString() << "at:";
-      for (int i=0; i<50; i++) {
-        qWarning() << reader->device()->readLine();
-      }
       r = Result(kXmlError);
-      r.SetDetails(reader->errorString());
+      r.SetDetails(QCoreApplication::translate("Serializer", "%1 on line %2").arg(reader->errorString(), QString::number(reader->lineNumber())));
     }
     r.SetLoadData(ld);
     return r;