* 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

* Fix #2619 - When redis feed is empty, fall back to database

* Use redis value to return feed from database only while RegenerationWorker
hasn't finished running

* Fix specs

* Replace usage of reject!

due to the change in #3373

* i18n: minor fix in Polish translation

* i18n

* Unread indicator was invisible behind column header, adjusted

* Unread indicator now a CSS pseudo-element

* Adjust flex

* Update Russian translation (pin)

follow up #3564

* Re-add clear notifications button

* remove connect() in column_settings

* one line

* remove unused props

* Use I18n.locale instead of ":en"
* Reset I18n.locale value after locale changing tests

* Update @storybook/addon-actions to v3.1.2

* Update @storybook/react to v3.1.2

* Update babel-core to v6.25.0

* Update babel-preset-env to v1.5.2

* Update chai to version v4.0.2

* Update extract-text-webpack-plugin to v2.1.2

* Update file-loader to v0.11.2

* Update intersection-observer to v0.3.0

* Update pg to v6.2.4

* Update sinon to v2.3.4

* Update style-loader to v0.18.2

* Update websocket.js to v0.1.10

* Update react-redux-loading-bar to v2.9.2

* yarn upgrade

TagManager.local_url? was sometimes called with an URI with a nil host,
leading to a crash in TagManager.local_url?. This fixes moves the
already-existing uri.host.blank? check in front to avoid this case.

Fix removal of status sending the original status to mentioned users instead of delete Salmon (#3672)

* Fix removal of status sending the original status to mentioned users instead
of delete Salmon, add test

* Create remove_status_service_spec.rb

* Move ancestors/descendants out of timelines reducer

* Refactor timelines reducer

All types of timelines now have a flat structure and use the same
reducer functions and actions

* Reintroduce some missing behaviours

* Fix wrong import in reports

* Fix includes typo

* Fix issue related to "next" pagination in timelines and notifications

* Fix bug with timeline's initial state, expandNotifications

```
DEPRECATION WARNING: The behavior of `attribute_changed?` inside of after callbacks will be changing in the next version of Rails. The new return value will reflect the behavior of calling the method after `save` returned (e.g. the opposite of what it returns now). To maintain the current behavior, use `saved_change_to_attribute?` instead. (called from block in <class:Account> at /Users/rene/Workspace/personal/ruby/mastodon/app/models/account.rb:60)
DEPRECATION WARNING: The behavior of `attribute_changed?` inside of after callbacks will be changing in the next version of Rails. The new return value will reflect the behavior of calling the method after `save` returned (e.g. the opposite of what it returns now). To maintain the current behavior, use `saved_change_to_attribute?` instead. (called from block in <class:Account> at /Users/rene/Workspace/personal/ruby/mastodon/app/models/account.rb:60)
DEPRECATION WARNING: The behavior of `attribute_changed?` inside of after callbacks will be changing in the next version of Rails. The new return value will reflect the behavior of calling the method after `save` returned (e.g. the opposite of what it returns now). To maintain the current behavior, use `saved_change_to_attribute?` instead. (called from block in <class:Account> at /Users/rene/Workspace/personal/ruby/mastodon/app/models/account.rb:60)
DEPRECATION WARNING: The behavior of `attribute_changed?` inside of after callbacks will be changing in the next version of Rails. The new return value will reflect the behavior of calling the method after `save` returned (e.g. the opposite of what it returns now). To maintain the current behavior, use `saved_change_to_attribute?` instead. (called from block in <class:Account> at /Users/rene/Workspace/personal/ruby/mastodon/app/models/account.rb:61)
DEPRECATION WARNING: The behavior of `attribute_changed?` inside of after callbacks will be changing in the next version of Rails. The new return value will reflect the behavior of calling the method after `save` returned (e.g. the opposite of what it returns now). To maintain the current behavior, use `saved_change_to_attribute?` instead. (called from block in <class:Account> at /Users/rene/Workspace/personal/ruby/mastodon/app/models/account.rb:62)
DEPRECATION WARNING: The behavior of `attribute_changed?` inside of after callbacks will be changing in the next version of Rails. The new return value will reflect the behavior of calling the method after `save` returned (e.g. the opposite of what it returns now). To maintain the current behavior, use `saved_change_to_attribute?` instead. (called from block in <class:Account> at /Users/rene/Workspace/personal/ruby/mastodon/app/models/account.rb:63)
```

Here's PR describing changes to Dirty API https://github.com/rails/rails/pull/25337

* Localize date in digest

* Cover NotificationMailer more

When case insensitivity is enabled via devise's `config.case_insensitive_keys` then `.find_for_authentication` method needs to be used instead of `.find_by` because second mentioned returns `nil` when valid email with different cases is passed.

More info https://github.com/plataformatec/devise/wiki/How-To:-Use-case-insensitive-emails

* Update mail to version 2.6.6

* Update aws-sdk to version 2.9.37

* Update capybara to version 2.14.2

* Update oj to version 3.1.0

* Update sidekiq to version 5.0.2

* Update puma to version 3.9.1

* Update sanitize to version 4.5.0

* Update capistrano-rails to version 1.3.0

- Use plaintext
- Strip out URLs
- Strip out mentions
- Strip out hashtags
- Strip out whitespace from "overall" count
- Consistent between JS and Ruby

* Improve default language decision

This change allows to takes account of accepted language determined by
the user agent even if the custom default locale of the instance is
configured.

* Cover Localized more

* Fix code style

Each of mute, favourite, reblog has been updated to:

- Have a separate controller with just a create and destroy action
- Preserve historical route names to not break the API
- Mild refactoring to break up long methods

* i18n

* i18n

* i18n

* i18n

* i18n

Move reblogged_by and favourited_by actions out of api/v1/statuses and into unique controllers (#3646)

* Add specs for api statuses routes

* Update favourited_by and reblogged_by api routes

* Move methods into new controllers

* Use load_accounts methods to simplify index actions

* Clean up load_accounts methods

* Clean up link header generation

* Check for link headers in specs

* Remove unused actions from api/v1/statuses controller

* Remove specs for moved actions

by using Array.prototype.indexOf instead

* Default to nil for statuses.language

* Language detection defaults to nil instead of instance UI default