improved how "show more" link looks

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

with YAML-defined defaults. Add admin page for editing global settings. Add "site_description"
setting that would show as a paragraph on the frontpage

for local attachments, use them in URLs. Check status privacy
before redirecting to actual file.

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

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 #233, fix #268

to the API

registration API

respect hub.lease_seconds (fix #46)

Adding better errors for the API controllers, posting a simple status works from the frontend now