nested inside a common parent (<Account>), instead they all embed <HeaderContainer />

Federate spoiler_text using warning attribute on <content /> instead of a <category term="spoiler" />
Clean up schema file from accidental development migrations

Filters out hidden stream entries from Atom feed
Blocks now generate hidden stream entries, can be used to federate blocks
Private statuses cannot be reblogged (generates generic 422 error for now)
POST /api/v1/statuses now takes visibility=(public|unlisted|private) param instead of unlisted boolean
Statuses JSON now contains visibility=(public|unlisted|private) field

Fix #205, fix #156, fix #124

Fix #233, fix #268

This makes the UI appear less laggy. After all, the status *is* created
right there and then, it's the distribution to home timelines that can take
a while

all statuses/accounts to assemble, but at least lists don't have to be
re-rendered all the time now. Also add "mention" dropdown option

Mostly resolves #8, though attachments are still not displayed in public view