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

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

* Fix regressions from #2683

Properly format spoiler text HTML, while keeping old logic for blankness intact
Process hashtags and mentions in spoiler text
Format spoiler text for Atom
Change "show more" toggle into a button instead of anchor
Fix style regression on dropdowns for detailed statuses

* Fix lint issue

* Convert spoiler text to plaintext in desktop notifications

* 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

There are multiple messages missing in en.jsx.
It is very troublesome when translating other languages.

from #1754, should close out #1394

* fix(classnames): Status icon style classnames

Take out inline css and put into classnames for the following components: account, avatar, icon button, status action bar, notification.

* fix(status): Move styles from inline to classes for statuses

Move styles to classnames in components.scss for the following components:

display name
media gallery
status
status content
video player

* fix(classnames): Add classnames to rest of components

Take out inline styles and apply them to classnames in the sass for the following components:

button
column back button
slim column back button
collapsable column
dropdown menu
loading indicator
status list

* fix(classnames): Remove all non-dynamic inline styles

Components affected:

autosuggested
permalink
action bar
header
character counter
compose form
emoji dropdown
privacy dropdown
reply indicator
upload form
account auth
followers
getting started
column settings
mutes
settings
reblogs
status checkbox
report
action bar
status
card
boost modal
media modal
video modal

* fix(permalink): Do not lose classname

* fix(tests): Add space back in display name

* fix(status__wrapper): Remove duplicate css name

Remove incorrect style attribute. Remove style attribute all together. Cursor defaults to "auto" when not specified as 'default'.

* fix(nl): do not lose translations

* Remove deprecated features at React v15.5

- [x] React.PropTypes
- [x] react-addons-pure-render-mixin
- [x] react-addons-test-utils

* Uncommented out & Add browserify_rails options

* re-add react-addons-shallow

* Fix syntax error from resolve conflicts

* follow up 59a77923b3

* jslint: remove trailing space

* jslint: fix no-nested-ternary issue

Follow the jslint [no-nested-ternary](http://eslint.org/docs/rules/no-nested-ternary)
rule. Rewritten ternary with if-then.

adjusted to allow choosing it, yet

nested inside a common parent (<Account>), instead they all embed <HeaderContainer />

Reflect "requested" relationship in API and UI
Reflect inability of private posts to be reblogged in the UI
Disable Webfinger for locked accounts

status clickable (this also fixes multiple dropdown being openable at the same
time)

all statuses/accounts to assemble, but at least lists don't have to be
re-rendered all the time now. Also add "mention" dropdown option