GUI - use QLocale's first of uiLanguages to get primary locale

This appears to work better with Big Sur.

Also improve locale logging.

Author: samaaron

app/gui/qt/main.cpp

@@ -49,8 +49,7 @@ int main(int argc, char *argv[])
 
   qRegisterMetaType<SonicPiLog::MultiMessage>("SonicPiLog::MultiMessage");
 
-  QString systemLocale = QLocale::system().name();
-
+  QString systemLocale = QLocale::system().uiLanguages()[0];
 
   QTranslator qtTranslator;
   qtTranslator.load("qt_" + systemLocale, QLibraryInfo::location(QLibraryInfo::TranslationsPath));

app/gui/qt/mainwindow.cpp

@@ -148,11 +148,20 @@ MainWindow::MainWindow(QApplication &app, bool i18n, QSplashScreen* splash)
 
     // Throw all stdout into ~/.sonic-pi/log/gui.log
     setupLogPathAndRedirectStdOut();
-
+    std::cout << "[GUI] -                            " << std::endl;
+    std::cout << "[GUI] -                            " << std::endl;
+    std::cout << "[GUI] -                            " << std::endl;
     std::cout << "[GUI] - Welcome to the Sonic Pi GUI" << std::endl;
     std::cout << "[GUI] - ===========================" << std::endl;
     std::cout << "[GUI] -                            " << std::endl;
     std::cout << "[GUI] - " << guiID.toStdString() << std::endl;
+    std::cout << "[GUI] - locale: " << QLocale::system().uiLanguages()[0].toStdString() << std::endl;
+
+    if(i18n) {
+      std::cout << "[GUI] - translations available " << std::endl;
+    } else {
+      std::cout << "[GUI] - translations unavailable (using EN)" << std::endl;
+    }
 
     // dynamically discover port numbers and then check them this will
     // show an error dialogue to the user and then kill the app if any of

app/server/ruby/bin/qt-doc.rb

@@ -216,7 +216,7 @@
   map { |p| File.basename(p).gsub(/sonic-pi-tutorial-(.*?).po/, '\1') }.
   sort_by {|n| -n.length}
 
-docs << "\n  QString systemLocale = QLocale::system().name();\n\n" unless languages.empty?
+docs << "\n  QString systemLocale = QLocale::system().uiLanguages()[0];\n\n" unless languages.empty?
 
 # first, try to match all non-default languages (those that aren't "en")
 languages.each do |lang|