more refactoring

src/App.js

src/components/features_panel/features_panel.js

src/components/login_form/login_form.js

src/components/post_status_form/post_status_form.js

src/components/registration/registration.js

src/components/settings/settings.js

src/components/settings/settings.vue

src/components/user_settings/user_settings.js

src/main.js

src/modules/instance.js

src/modules/interface.js