Feature selector (#4074)

* WIP

* ParityBar verification

* import from index.js

* i18n expansion & tests

* Features component

* Adapt language selector to use features

* Add features to settings view

* typo

* Convert logging

* Fix earlier merge issues resulting in test failures

* Lint failure fixes (new rules)

* Fix additional listing rules

* Re-add FormattedMessage (missing after merge), fix tests

* Fix loader overrides

* grumble: split item rendering (& test)

* grumble: allow enable/disable while testing (default on)

* grumble: move LanguageSelector below Features

* grumble: don't pass visiblity prop (& update tests)

* grumble: missing observable (onClick misbehaving)

* grumble: don't reset to defaults per session

* Fix to single store instance

js/webpack/app.js

@@ -117,8 +117,13 @@ module.exports = {
         test: /\.(woff(2)|ttf|eot|otf)(\?v=[0-9]\.[0-9]\.[0-9])?$/,
         use: [ 'file-loader?name=fonts/[name][hash:10].[ext]' ]
       },
+      {
+        test: /parity-logo-white-no-text\.svg/,
+        use: [ 'url-loader' ]
+      },
       {
         test: /\.svg(\?v=[0-9]\.[0-9]\.[0-9])?$/,
+        exclude: [ /parity-logo-white-no-text\.svg/ ],
         use: [ 'file-loader?name=assets/[name].[hash:10].[ext]' ]
       }
     ],