* Add tests

* Fix some link previews being incorrectly generated from different prior links

PR #12403 added a cache to avoid redundant queries when the OEmbed endpoint can
be guessed from the URL. This caching mechanism is not perfectly correct as
there is no guarantee that all pages from a given domain share the same
OEmbed provider endpoint.

This PR prevents the FetchOEmbedService from caching OEmbed endpoint that
cannot be generalized by replacing a fully-qualified URL from the endpoint's
parameters, greatly reducing the number of incorrect cached generalizations.

* Switch from unmaintained paperclip to kt-paperclip

* Drop some compatibility monkey-patches not required by kt-paperclip

* Drop media spoof check monkey-patching

It's broken with kt-paperclip and hopefully it won't be needed anymore

* Fix regression introduced by paperclip 6.1.0

* Do not rely on pathname to call FastImage

* Add test for ogg vorbis file with cover art

* Add audio/vorbis to the accepted content-types

This seems erroneous as this would be the content-type for a vorbis stream
without an ogg container, but that's what the `marcel` gem outputs, so…

* Restore missing for_as_default method

* Refactor Attachmentable concern and delay Paperclip's content-type spoof check

Check for content-type spoofing *after* setting the extension ourselves, this
fixes a regression with kt-paperclip's validations being more strict than
paperclip 6.0.0 and rejecting some Pleroma uploads because of unknown
extensions.

* Please CodeClimate

* Add audio/vorbis to the unreliable set

It doesn't correspond to a file format and thus has no extension associated.

* Change references to tootsuite/mastodon to mastodon/mastodon

* Remove obsolete test fixture

* Replace occurrences of tootsuite/mastodon with mastodon/mastodon in CHANGELOG

And a few other places

* Add ability to export bookmarks

* Add support for importing bookmarks

* Add bookmark import tests

* Add bookmarks export test

* Remove Salmon and PubSubHubbub endpoints

* Add error when trying to follow OStatus accounts

* Fix new accounts not being created in ResolveAccountService

* Refactor imports

* Export show_reblogs when exporting list of followed users

* Add support for importing show_reblogs with following collection

* Fix tests

* Export hide_notifications along with user mutes

* Import hide_notifications along with muted users list

* Add headers for CSV exports

* Fix undefined method error in sidekiq

Body can be not nil but still be empty, which causes a
`NoMethodError: undefined method `[]' for nil:NilClass` further in the
code. This checks for an empty body to avoid the issue.

* Fix codeclimate issue

* Add failing test for windows-1251 link cards

* Ignore low-confidence CharlockHolmes guesses

Fixes #9466

* Fix no method error when charlock holmes cannot detect charset

* Error message for avatar image that's too large. #9204

* Code climate/formatting

* Removed avatar error message

* Moved valid image dimentions check to update service

* removed unnescessary begin block

* code climate formatting

* code climate indent fix

* No need to re-require sidekiq plugins, they are required via Gemfile

* Add derailed_benchmarks tool, no need to require TTY gems in Gemfile

* Replace ruby-oembed with FetchOEmbedService

Reduce startup by 45382 allocated objects

* Remove preloaded JSON-LD in favour of caching HTTP responses

Reduce boot RAM by about 6 MiB

* Fix tests

* Fix test suite by stubbing out JSON-LD contexts

* Add equals_or_includes_any? helper in JsonLdHelper

* Support arrays in JSON-LD type fields for actors/tags/objects.

* Spec for resolving accounts with extension types

* Style tweaks for codeclimate

* Added #link_header spec

* Added #call spec

* Delete spec of private methods

* Added #call spec

Looks like copied tempfile need to be flushed before further processing. This issue won't happen if the uploaded file has enough file size.

* Custom emoji

- In OStatus: `<link rel="emoji" name="coolcat" href="http://..." />`
- In ActivityPub: `{ type: "Emoji", name: ":coolcat:", href: "http://..." }`
- In REST API: Status object includes `emojis` array (`shortcode`, `url`)
- Domain blocks with reject media stop emojis
- Emoji file up to 50KB
- Web UI handles custom emojis
- Static pages render custom emojis as `<img />` tags

Side effects:

- Undo #4500 optimization, as I needed to modify it to restore
  shortcode handling in emojify()
- Formatter#plaintext should now make sure stripped out line-breaks
  and paragraphs are replaced with newlines

* Fix emoji at the start not being converted

* Fix an error when actor json couldn't be fetched in ResolveRemoteAccountService

* Add specs

* Specs for language detection

* Use CharlockHolmes instead of NKF

* Correct mistakes

* Correct style

* Set hint_enc instead of falling back and strip_tags

* Improve specs

* Add dependencies

* Do not default the format in ProviderDiscovery

The format should be determined when discovering, as it is in the current
implementation, and it is a flaw if it is not determined.

* Spec ProviderDiscovery

* 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 #2108 - Fix gif uploads
Add specs for media attachment gifv conversion

* Add ffmpeg to travis

* Make travis install ffmpeg, not libav

* Switch travis to trusty

* Add spec for settings/imports controller

* Add failing spec for settings/imports#create

* Fix broken imports

* Refactor ImportWorker

* When avatar/header are GIF, generate static versions.
Account API returns "avatar"/"avatar_static", "header"/"header_static"
Static version is the same as original for other cases
Web UI de-animates avatars in toots, lists of users

Fix #441, fix #596, prerequisite for #1064

* Fix JS test

* Add rake task to generate static avatars/headers from GIF ones, add test

timeline reload in UI, other small fixes