message: [crispy] App: enable logging via LOG env-var for any App{} instance.
diff: @@ -120,6 +120,12 @@ App::App(std::string _appName, std::string _appTitle, std::string _appVersion, s
  appLicense_ { std::move(_appLicense) },
  localStateDir_ { xdgStateHome() / appName_ }
  {
  + if (char const* logFilterString = getenv("LOG"))
  + {
  + logstore::configure(logFilterString);
  + customizeLogStoreOutput();
  + }
  +
  instance_ = this;
  link(appName_ + ".help", bind(&App::helpAction, this));
  