* Fix #3910 - Require OTP authentication to disable 2FA. Also, remove ability
to generate new OTP backup codes *after* initial backup codes were handed
out during activation

* Restore recovery code re-generation

* Improve display of some 2FA elements

* Add overview of active sessions

* Better display of browser/platform name

* Improve how browser information is stored and displayed for sessions overview

* Fix test

* Remove unused column_collapsable.js
* Remove old styles
* Extract `> div`  style to independent class

* Replace TextIconButton for SensitiveButton to IconButton

* line-height

* Add form for account deletion

* If avatar or header are gone from source, remove them

* Add option to have SuspendAccountService remove user record, add tests

* Exclude suspended accounts from search

* Unread indicator was invisible behind column header, adjusted

* Unread indicator now a CSS pseudo-element

* Adjust flex

* Re-add clear notifications button

* remove connect() in column_settings

* one line

* remove unused props

* Add explit admin actions to (re)subscribe/unsubscribe remote accounts
and re-download avatar/header

* Improve how admin NSFW toggle looks

before the full-size image is loaded

* Add regex filter on the community timeline and the public timeline

* correcting

* Adjust the height of header buttons

* Remove trailing spaces

* Remove trailing spaces

* Solve some code duplication

* reset the state of the locale files in app/javascript/mastodon/locales

* adjust to upstream

* adjust to upstream

* change keys of locale settings

* Add support key shortcut to Onboarding Modal

* this.state.pages -> this.pages

* Allow mounting arbitrary columns

* Refactor column headers, allow pinning/unpinning and moving columns around

* Collapse animation

* Re-introduce scroll to top

* Save column settings properly, do not display pin options in
single-column view, do not display collapse icon if there is
nothing to collapse

* Fix one instance of public timeline being closed closing the stream
Fix back buttons inconsistently sending you back to / even if history exists

* Getting started displays links to columns that are not mounted

* Remove react-imageloader

* add eslint-disable-line

* improve image loading experience

* remove unneeded import

* use PureComponent

* Use componentWillMount instead of constructor

The combination of object-fit, relative position 50% from top and translating it
back upwards 50% is what allows us to crop the video properly, so it needs to
be +50%-50%

on status fade-in, fix buttons not having pointer cursor

Fix warning for ESLint (jsx-a11y/href-no-hash).

Fixes #3277. I've tested in QupZilla on Mac and can confirm it fixes the issue, and that Chrome 58 is not affected (because it has Grid).

* Add load more button for large screens
* Fix `next` state value on the first loading
* Don't load if `isLoading || !hasMore`
* Start load on near the bottom

* 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.

* Remove allowed_languages and add filtered_languages

* Use filtered_languages instead of allowed_languages

* Add account media gallery view to web UI

* Link media view from account dropdown

* Adjust link

react-autosuggest is added from c49f6290eb

Dependence removed from b27066e154

* Always set `overflow: auto` to allow scroll just after opening
* Remove bounce animation which may cause unintended behavior due to max-height
* Use CSS transition instead of react-motion
* Some CSS refactoring including className changing

From #2327 - Elephant friend was overlapping with text, oversized in
single column layout

From #2021 - Centered layout goes against design principles, changes
UX for everybody who's already used to the current one

From #2271 - CPU/RAM overusage from keeping columns in DOM (fix #2648,
possibly also #2101)

Resolves #2515

* Fix color contrast some more in privacy warning

Latest master appears to have changed the <strong> to this unreadable grey color. If you want that to be white then it should be pure white. If someone would rather revert this to that strong dark blue color it was before that would be good too.

* Make domain dark blue again

* add missing ;

woops

* Allow SCSS variables to be overridden with
  `app/javascript/pack/variables*.scss`

* Allow these SCSS variables to be overriden:
  * `$base-shadow-color`
  * `$base-overlay-background`
  * `$base-border-color`
  * `$simple-background-color`
  * `$primary-text-color`
  * `$valid-value-color
  * `$error-value-color`