Release v0.6.18: verify conversion results and log problems only

src/platform.h

@@ -66,6 +66,7 @@ class DiagnosticBuffer
 };
 void setLoggingEnabled(bool enabled);
 void diagnosticEvent(const std::wstring &message, bool problem = false);
+void diagnosticOperation(const std::string &json);
 std::wstring readDiagnosticLog(bool previous);
 void clearDiagnosticLog(bool previous);
 } // namespace ks