Allow setting custom config file with --config option

src/main.cpp

@@ -54,7 +54,7 @@ int main(int argc, char *argv[])
     app.setApplicationName(QStringLiteral("kdenlive"));
     app.setWindowIcon(QIcon(":/pics/kdenlive.png"));
     KLocalizedString::setApplicationDomain("kdenlive");
-    KSharedConfigPtr config = KSharedConfig::openConfig(QStringLiteral("kdenliverc"));
+    KSharedConfigPtr config = KSharedConfig::openConfig();
     KConfigGroup grp(config, "unmanaged");
     KConfigGroup initialGroup(config, "version");
     if (!initialGroup.exists()) {
@@ -118,6 +118,7 @@ int main(int argc, char *argv[])
     parser.addVersionOption();
     parser.addHelpOption();
 
+    parser.addOption(QCommandLineOption(QStringList() <<  QStringLiteral("config"), i18n("Set a custom config file name"), QStringLiteral("config")));
     parser.addOption(QCommandLineOption(QStringList() <<  QStringLiteral("mlt-path"), i18n("Set the path for MLT environment"), QStringLiteral("mlt-path")));
     parser.addOption(QCommandLineOption(QStringList() <<  QStringLiteral("i"), i18n("Comma separated list of clips to add"), QStringLiteral("clips")));
     parser.addPositionalArgument(QStringLiteral("file"), i18n("Document to open"));