- Upgrade dependencies
    - chai (3.5.0 -> 4.0.1)
    - chai-enzyme (0.6.1 -> 0.7.1)
    - sinon (2.2.0 -> 2.3.2)
- Change extensions from .jsx to .js
- Don't assign `React` to `global`
- Check code format using ESLint

* Remove react-imageloader

* add eslint-disable-line

* improve image loading experience

* remove unneeded import

* use PureComponent

* Use componentWillMount instead of constructor

* Update autoprefixer to version 7.1.0

* Update axios to version 0.16.1

* Update babel-cli to version 6.24.1

* Update babel-eslint to version 7.2.3

* Update babel-preset-react to version 6.24.1

* Update coffee-script to version 1.12.6

* Update css-loader to version 0.28.1

* Update express to version 4.15.2

* Update js-yaml to version 3.8.4

* Update mocha to version 3.4.1

* Update jsdom to version 10.1.0

* Update npmlog to version 4.1.0

* Update postcss-smart-import to version 0.7.0

* Update postcss-loader to version 2.0.5

* Update pg to version 6.1.5

* Update prop-types to version 15.5.10

* Update rails-ujs to version 5.1.1

* Update redis to version 2.7.1

* Update sass-loader to version 6.0.5

* Update stringz to version 0.2.0

* Update webpack to version 2.5.1

* Update style-loader to version 0.17.0

* Update sinon to version 2.2.0

* Update react-motion to version 0.5.0

* Update react-notification to version 6.7.0

* Update react-redux-loading-bar to version 2.9.0

* Update react-intl to version 2.3.0

* Update redux-immutable to version 4.0.0

* Update reselect to version 3.0.1

* Update react-toggle to version 3.0.1

* Update react-simple-dropdown to version 3.0.0

* Update react-router to version 3.0.5

* Update react-router-scroll to version 0.4.2

* Update react-toggle to version 4.0.1

* yarn upgrade

* Improve streaming API cluster logging

* Less verbose error middleware logging (stack trace useless there)

* Fix error logging

* Prevent potential issue

* Add missing "done()" in catch of Promise.all, websocket heartbeat re-implemented like in example

* I actually forgot a done(), the absolute madman

* refactor(components/status_list): Lazy load using IntersectionObserver

* refactor(components/status_list): Avoid setState bottleneck

* refactor(components/status_list): Update state correctly

* fix(components/status): Render if isIntersecting is undefined

* refactor(components/status): Recycle timeout

* refactor(components/status): Reduce animation duration

* refactor(components/status): Use requestIdleCallback

* chore: Split polyfill bundles

* refactor(components/status_list): Increase rootMargin to 300%

* fix(components/status): Check if onRef is not defined

* chore: Add note about polyfill bundle splitting

* fix(components/status): Reduce animation duration to 0.3 seconds

Focus the submit button when confirmation modal is opened.

Also, changed cancellation link to button.
This makes the meaning clearer.

* Only load Intl data for current language

* Extract common chunk only from application.js and public.js

* Generate locale packs, avoid caching on window object

* Add semi to ESLint rules

* Add padded-blocks to ESLint rules

* Add comma-dangle to ESLint rules

* add config/webpack and storyboard

* add streaming/

* yarn test:lint -- --fix

react-autosuggest is added from c49f6290

Dependence removed from b27066e1

In Code Climate, eslint-plugin-jsx-a11y v4.0.0 is used.
Therefore, it seems that a warning is displayed.

ref https://github.com/codeclimate/codeclimate-eslint/pull/273

* feat(babel): Strip prop types

* chore(babel): Indent

* fix(babel): Move babel-plugin-transform-react-remove-prop-types to dependencies

* Use babel-preset-env on Streaming Server

Change the streaming server to use babel-preset-env as well as asset compilation.
This shortens the load time at first boot.

* remove babel-plugin-lodash

* Remove Babel plugin for ES Modules

Processing of ES Modules is executed by Webpack.
Don't have to do it on Babel side.

* Add plugin for test

Got an error in asset precompile on Heroku:
Module build failed: Error: ENOENT: no such file or directory, scandir '/tmp/.../node_modules/node-sass/vendor'

ref: https://github.com/rails/webpacker#troubleshooting

Use ES Class Fields & Static Properties (currently stage 2) for improve class outlook.

Added babel-plugin-transform-class-properties as a Babel plugin.

There are some dependencies that are no longer needed anymore.
As a result, it took more time to install the package than necessary.

I want to delete them and shorten the installation time.

Fixes #2941

* Remove jquery-ujs

* fix for eslint

* eslintrc: adapt changes in eslint-plugin-jsx-a11y

* Replace 'jsx-a11y/img-has-alt' with 'jsx-a11y/alt-text'.
  Reference: evcohen/eslint-plugin-jsx-a11y@24b6193

* Replace 'jsx-a11y/onclick-has-focus' with 'jsx-a11y/interactive-supports-focus'
  Reference: evcohen/eslint-plugin-jsx-a11y@cbdfeb8

* Replace 'jsx-a11y/onclick-has-role' with 'jsx-a11y/no-noninteractive-element-interactions'
  Reference: evcohen/eslint-plugin-jsx-a11y@18c9b71

* Update eslint-plugin-jsx-a11y to 5.0.0

Follow the change in Code Climate. Make sure the same eslintrc
can be executed locally and in Code Climate.

* Convert .eslintrc.json to equivlant .eslintrc.yml

* Less quotes and commas, more readability, allow comment.

* Replace ws with uws

* fix indent

* Adjust indentation

* remove trailing space

* package.json: Add "build:*" targets

* Improve react-intl-translations-manager workflow.
  * Added "build:production" to build production bundle.
  * Added "build:development" to build development bundle.

* Fix json translation files

* Run `yarn manage:translations` to fix translation files.
* Fix `pl.json` for syntax error.

* translationRunner: auto detect existing languages

* Auto detect existing rfc5646 language tag in *.json filenames
  in `app/javascript/mastodon/locale` folder. No need to manually
  define every new language in the languages array here.

* translationRunner: add more functionality

* Allow script user to specify language code to check.
* Added available language check.
* Added --force flag to force creation of unexists language.
* Added --help flag and help messages.

* gitignore: ignore npm-debug.log

* Fix webpack error if NODE_ENV is not defined

Default to use 'development' in config/webpack/configuration.js