"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

Make the streaming API also handle websockets (because trying to get the browser EventSource interface to
work flawlessly was a nightmare). WARNING: This commit makes the web UI connect to the streaming API instead
of ActionCable like before. This means that if you are upgrading, you should set that up beforehand.

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

the public timeline has been using

button takes you back to getting started page

This prevents the bug where if you go "back" to the UI after navigating to
another page it loads with the old set of statuses

Also upgrade react-redux to latest version. This is a performance update