Replace sprockets/browserify with Webpack (#2617)

* Replace browserify with webpack

* Add react-intl-translations-manager

* Do not minify in development, add offline-plugin for ServiceWorker background cache updates

* Adjust tests and dependencies

* Fix production deployments

* Fix tests

* More optimizations

* Improve travis cache for npm stuff

* Re-run travis

* Add back support for custom.scss as before

* Remove offline-plugin and babili

* Fix issue with Immutable.List().unshift(...values) not working as expected

* Make travis load schema instead of running all migrations in sequence

* Fix missing React import in WarningContainer. Optimize rendering performance by using ImmutablePureComponent instead of
React.PureComponent. ImmutablePureComponent uses Immutable.is() to compare props. Replace dynamic callback bindings in
<UI />

* Add react definitions to places that use JSX

* Add Procfile.dev for running rails, webpack and streaming API at the same time

config/application.rb

@@ -74,10 +74,6 @@ module Mastodon
     config.middleware.use Rack::Attack
     config.middleware.use Rack::Deflater
 
-    # babel config can be found in .babelrc
-    config.browserify_rails.commandline_options   = '--transform babelify --extension=".jsx"'
-    config.browserify_rails.evaluate_node_modules = true
-
     config.to_prepare do
       Doorkeeper::AuthorizationsController.layout 'public'
       Doorkeeper::AuthorizedApplicationsController.layout 'admin'