Merge remote-tracking branch 'origin/master' into gs-master

Conflicts:
 	.travis.yml
 	Gemfile.lock
 	README.md
 	app/controllers/settings/follower_domains_controller.rb
 	app/controllers/statuses_controller.rb
 	app/javascript/mastodon/locales/ja.json
 	app/lib/feed_manager.rb
 	app/models/media_attachment.rb
 	app/models/mute.rb
 	app/models/status.rb
 	app/services/mute_service.rb
 	app/views/home/index.html.haml
 	app/views/stream_entries/_simple_status.html.haml
 	config/locales/ca.yml
 	config/locales/en.yml
 	config/locales/es.yml
 	config/locales/fr.yml
 	config/locales/nl.yml
 	config/locales/pl.yml
 	config/locales/pt-BR.yml
 	config/themes.yml

app/models/media_attachment.rb

@@ -3,8 +3,8 @@
 #
 # Table name: media_attachments
 #
-#  id                :integer          not null, primary key
-#  status_id         :integer
+#  id                :bigint(8)        not null, primary key
+#  status_id         :bigint(8)
 #  file_file_name    :string
 #  file_content_type :string
 #  file_file_size    :integer
@@ -15,12 +15,10 @@
 #  shortcode         :string
 #  type              :integer          default("image"), not null
 #  file_meta         :json
-#  account_id        :integer
+#  account_id        :bigint(8)
 #  description       :text
 #
 
-require 'mime/types'
-
 class MediaAttachment < ApplicationRecord
   self.inheritance_column = nil
 
@@ -90,6 +88,8 @@ class MediaAttachment < ApplicationRecord
   validates_attachment_size :file, less_than: LIMIT
   remotable_attachment :file, LIMIT
 
+  include Attachmentable
+
   validates :account, presence: true
   validates :description, length: { maximum: 420 }, if: :local?
 
@@ -247,13 +247,4 @@ class MediaAttachment < ApplicationRecord
       bitrate: movie.bitrate,
     }
   end
-
-  def appropriate_extension
-    mime_type = MIME::Types[file.content_type]
-
-    extensions_for_mime_type = mime_type.empty? ? [] : mime_type.first.extensions
-    original_extension       = Paperclip::Interpolations.extension(file, :original)
-
-    extensions_for_mime_type.include?(original_extension) ? original_extension : extensions_for_mime_type.first
-  end
 end