* Add <ostatus:conversation /> tag to Atom input/output

Only uses ref attribute (not href) because href would be
the alternate link that's always included also.

Creates new conversation for every non-reply status. Carries
over conversation for every reply. Keeps remote URIs verbatim,
generates local URIs on the fly like the rest of them.

* Conversation muting - prevents notifications that reference a conversation
(including replies, favourites, reblogs) from being created. API endpoints
/api/v1/statuses/:id/mute and /api/v1/statuses/:id/unmute

Currently no way to tell when a status/conversation is muted, so the web UI
only has a "disable notifications" button, doesn't work as a toggle

* Display "Dismiss notifications" on all statuses in notifications column, not just own

* Add "muted" as a boolean attribute on statuses JSON

For now always false on contained reblogs, since it's only relevant for
statuses returned from the notifications endpoint, which are not nested

Remove "Disable notifications" from detailed status view, since it's
only relevant in the notifications column

* Up max class length

* Remove pending test for conversation mute

* Add tests, clean up

* Rename to "mute conversation" and "unmute conversation"

* Raise validation error when trying to mute/unmute status without conversation

* Adding account domain blocks that filter notifications and public timelines

* Add tests for domain blocks in notifications, public timelines
Filter reblogs of blocked domains from home

* Add API for listing and creating account domain blocks

* API for creating/deleting domain blocks, tests for Status#ancestors
and Status#descendants, filter domain blocks from them

* Filter domains in streaming API

* Update account_domain_block_spec.rb

The `Status` class has a default order on it, so when this query gets built and
gets all the way to `find_in_batches` there is an order already there.

When `find_in_batches` is run it discards any existing order on the query, and
emits a warning to the logs if there is one there.

This change removes the order prior calling `find_in_batches`, which will stop
the logged warning from occurring as well.

By pushing this into a worker we can reduce the amount of time the feed manager using workers eat up a connection

make regeneration worker unique, (only schedule/execute once at a time)

do not re-create a dynamic class on each feed push call, make sure redis-rb uses hiredis

adjusted to allow choosing it, yet

reinsert it when someone boosts it

status is not in the system at time of distribution; fix #607 - reset privacy
settings to defaults when cancelling replies

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

background as well since it's a computationally expensive

now return empty hash instead of throwing a 404 error. When following,
merge into timeline will filter statuses

resolving the confusion from self-chain replies ultimately linking to a
non-self status. Adjust filters

Reflect "requested" relationship in API and UI
Reflect inability of private posts to be reblogged in the UI
Disable Webfinger for locked accounts

who don't follow them

to be more readable, add extra logging to process feed service