Logging can be enabled in release build like this:
QT_LOGGING_RULES="fernschreiber.*=true" harbour-fernschreiber
See https://doc.qt.io/qt-5/qloggingcategory.html for more details.
Profile images seem to be loading significantly faster after
moving file fetching logic to the native code and removing the
artificial delay.
TDLibFile is a generic object which can hopefully be used
elsewhere as an efficient replacement for JavaScript.
