1. Use unified function names `initInstance()` and `freeInstance()` and
make them public.
2. Add `freeInstance()` to avoid noise from memory leak detectors.
3. Let `instance()`return a pointer directly to avoid unnecessary
indirections when invoking functions.
Logger::instance()->addMessage(tr("Redundant command line flag detected: \"%1\". Portable mode implies relative fastresume.").arg("--relative-fastresume"),Log::WARNING);// to avoid translating the `--relative-fastresume` string
Logger::instance()->addMessage(tr("Redundant command line flag detected: \"%1\". Portable mode implies relative fastresume.").arg("--relative-fastresume"),Log::WARNING);// to avoid translating the `--relative-fastresume` string