In #2110, a new attachment type "unknown" was introduced for
attachments that were rejected due to a domain being blocked using
reject_media. However, the "type" field was never set to "unknown"
because a default value of "0" (image) is set for that column,
causing the `type.blank?` expression to always equal false.

This version uses type_changed? instead, causing the type to be set
to "unknown" unless a type has been explicitly set. This introduces
a small change in behaviour causing the type to be set to unknown
before paperclip calls `before_post_process`. Presumably this
behaviour is more appropriate than the current one because the
attachment type has not been determined by that point.

Included are new tests for `ProcessFeedService` and
`UpdateRemoteProfileService` which now check that remote media is
downloaded for non-blocked domains and is rejected for others.

* Instead of parsing shared status contents verbatim, make roundtrip
to purported original URL. Confirm that the "original" URL is from the
same domain as the author it claims to be from.

* Fix obvious typo, add comment

* Use URI look-up first

* Add test, update Goldfinger dependency to make less useless HTTP requests per Webfinger lookup

* OEmbed support for PreviewCard

* Improve ProviderDiscovery code failure treatment

* Do not crawl links if there is a content warning, since those
don't display a link card anyway

* Reset db schema

* Fresh migrate

* Fix rubocop style issues
Fix #1681 - return existing access token when applicable instead of creating new

* Fix test

* Extract http client to helper

* Improve oembed controller

* Add coverage for domain block service with silence

* Get rid of warning about find_each and order

* Move domain_block to attr_reader

* Move optional clear_media into silence_accounts method

* Use blocked_domain method to reduce passed vars

* Extract blocked_domain_accounts method to find accounts on the domain

* Extract media_from_blocked_domain method to find relevant attachments

* Separate destruction of account images and account attachments

duplicates. Web UI regenerates UUID for that header every time the compose
form is changed or successfully submitted

Also, fix Farsi i18n overwriting the English one

* Fix #2119 - Whenever about to send a HTTP request, normalize the URI

* Add test for IDN request in FetchLinkCardService

* Perform IDN normalization on domains before they are stored in the DB

* Fix possibility of unrightful webfinger redirect

* Add more tests for FollowRemoteAccountService

* Extract detect_language to separate class

* Use default locale, not just en

* Add spec to confirm that whatlanguage cant identify empty string

* Allow account locale to override default in language detector

* PostStatusService supplies an account to detect language

* Begin coverage for account search service

* Coverage for hashtag query

* Coverage for calling local vs remote find based on domain presence

* Spec to check that exact matches are not duped

* Coverage of resolve option

* Coverage for account being provided

* Start to refactor account search service

* Isolate query username and domain methods

* Isolate exact_match method

* Extract methods for local and remote results

* Simplify local vs remote and account isoliation

* Extract methods for local and remote results

* Simplify de-dupe of exact match

* Simplify logic to check for non exact remotes

* Cache some methods

* Remove nil from exact_match from results array

* Return exact matches first

* Use find_remote even with no domain

Account.find_local is just an alias for Account.find_remote(user, nil) - so we
can not bother with the conditional here, and call find_remote directly.

* Fix #1141, fix #1126 - Work through UpdateRemoteProfileService for both <feed> and <entry> top-level tags

* Improve code quality, remove line unrelated to fix

These are currently user facing errors, but are not localized. This adds the
ability for these messages to be localized.

This implements all pending specs, and adds additional coverage for the
following functionality:

* Normal status creation
* Creating a reply status
* Creating a sensitive status
* Creating a status with spoiler text
* A status with no spoiler text gets an empty string for spoiler text
* Creating a status with custom visibility
* Creating a status for an application
* Processing mentions
* Processing Hashtags
* Pinging PuSH hubs
* Crawling links
* Attaching media

There are currently not specs for the two media validations that are performed
by `PostStatusService`. This adds specs for the validations that ensure that you
cannot attach more than four files, and that a status cannot have both image and
video attachments.

StreamEntry model. Simply render Salmon slaps as they are needed

redis-backed "mentions" timeline as redundant (given notifications)

removing web app capability from non-webapp pages

Fetching atom extracted from FetchRemoteAccountService and FetchRemoteStatusService
into FetchAtomService. Mentions of the constant "http://activityschema.org/collection/public"
skipped as it's not a real URL/user.