Cleanup Argument parser.

Use QCommandLineParser instead of buggy hand crafted one.

src/main.cpp

@@ -72,12 +72,6 @@ int main(int argc, char * argv[]) {
     QCoreApplication::setApplicationName(Version::applicationName());
     QCoreApplication::setApplicationVersion(Version::version());
 
-    // Construct a list of strings based on the command line arguments
-    CmdlineArgs& args = CmdlineArgs::Instance();
-    if (!args.Parse(argc, argv)) {
-        args.printUsage();
-        return kParseCmdlineArgsErrorExitCode;
-    }
 
     // If you change this here, you also need to change it in
     // ErrorDialogHandler::errorDialog(). TODO(XXX): Remove this hack.
@@ -90,6 +84,11 @@ int main(int argc, char * argv[]) {
 
     MixxxApplication app(argc, argv);
 
+    // Construct a list of strings based on the command line arguments
+    CmdlineArgs& args = CmdlineArgs::Instance();
+    if (!args.Parse(app.arguments())) {
+        return kParseCmdlineArgsErrorExitCode;
+    }
 
 #ifdef __APPLE__
     QDir dir(QApplication::applicationDirPath());

src/test/mixxxtest.cpp

@@ -25,7 +25,12 @@ QScopedPointer<MixxxApplication> MixxxTest::s_pApplication;
 MixxxTest::ApplicationScope::ApplicationScope(int& argc, char** argv) {
     // Construct a list of strings based on the command line arguments
     CmdlineArgs args;
-    const bool argsParsed = args.Parse(argc, argv);
+    QStringList argList;
+    for (int i = 0; i < argc; i++) {
+        argList << QString::fromLocal8Bit(argv[i]);
+    }
+
+    const bool argsParsed = args.Parse(argList);
     Q_UNUSED(argsParsed);
     DEBUG_ASSERT(argsParsed);