Returns accounts, statuses, hashtags arrays

"Various apps are available" is now a hyperlink

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

StreamEntry model. Simply render Salmon slaps as they are needed

This should help federation

to only those from local users; Add link to "extended information" to
getting started in the UI; Add defaults for posting privacy; Change
how publish button looks depending on posting privacy chosen

untested, my vagrant is bugged again, submitted at gargron's request

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.