* 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

* Add exclude_types param to /api/v1/notifications

* Exclude notification types in web UI through exclude_types in the API

* Consolidate webfinger string creation under Account#to_webfinger_s

* Introduce Account#local_username_and_domain for consolidation

* Clean up SQL output in Tag and Account search methods

* Add basic coverage for Tag.search_for

* Add coverage for Account.search_for

* Add coverage for Account.advanced_search_for

* Fix #795, fix #704, fix #835 - 2FA requires confirmation to be enabled
TOTP secret is not shown again after 2FA is enabled

* Clean up

Checking reblog vs original status was happening in multiple places
across the app. For views, this logic was encapsulated in a helper
method named `proper_status` but in the other layers of the app, the
logic was duplicated.

Because the logic is used at all layers of the app, we extracted it into
a `Status#proper` method on the model and changed all uses of the logic
to use this method. There is now a single source of truth for this
condition.

We added test coverage to untested methods that got refactored.

* Rewrite Atom generation from stream entries to use Ox instead of Nokogiri::Builder

StreamEntry is now limited to only statuses, which allows some optimization. Removed
extra queries on AccountsController#show. AtomSerializer instead of AtomBuilderHelper
used in AccountsController#show, StreamEntriesController#show, StreamEntryRenderer
and PubSubHubbub::DistributionWorker

PubSubHubbub::DistributionWorker moves n+1 DomainBlock query to PubSubHubbub::DeliveryWorker
instead.

All Salmon slaps that aren't based on StreamEntry still use AtomBuilderHelper and Nokogiri

* All Salmon slaps now use Ox instead of Nokogiri. No touch from status on account

add ability to open status by URL from search (fix #53)

Returns accounts, statuses, hashtags arrays

adjusted to allow choosing it, yet

(Because postgres can tell that count(*) needs no extra checks, but
counting a specific column requires them)

Fix anchor tags in some wikipedia URLs being matches as a hashtag

Redirect /:username to /users/:username
Redirect /:username/:id to /users/:username/updates/:id
Updated API documentation and sponsors

before. In the API, attachments now can be either image, video or gifv. Gifv
is to be treated like images in terms of behaviour, but are videos by file
type.

Add ability to search accounts by display name

"whole known network" which is what public timeline used to be

Only domain blocks with suspend severity will block PuSH subscriptions
Silenced accounts should not appear in conversations unless followed

StreamEntry model. Simply render Salmon slaps as they are needed

Allow PuSH to distribute private toots with that condition