Fix varnish chunked and general improvements

See merge request pleroma/pleroma!653

Support activity+json request for activity

See merge request pleroma/pleroma!641

This enables caching/streaming of chunked responses

Support more filetypes for caching static media

Add Twitter Card parser

See merge request pleroma/pleroma!643

Twapi follower pagination

See merge request pleroma/pleroma!648

common api: fix newlines in markdown code blocks

See merge request pleroma/pleroma!651

ok @lanodan

Pinned Statuses

Closes #440

See merge request pleroma/pleroma!636

Mass follow

See merge request pleroma/pleroma!642

Add activity visibility index.

See merge request pleroma/pleroma!646

Alpha sort the restricted nicknames

See merge request pleroma/pleroma!650

Rich media: Remove :commit since a tuple is already returned

See merge request pleroma/pleroma!649

Scarlett/pleroma summary html api

See merge request pleroma/pleroma!647

```
# Only return statuses that have been pinned
GET /api/statuses/user_timeline.json?pinned=true

# Pin
POST /api/statuses/pin/:id

# Unpin
POST /api/statuses/unpin/:id
```

# Conflicts:
#	docs/config.md

user: fix local vs remote determination in remote_or_auth_active?/1

See merge request pleroma/pleroma!640

any actual callee will be dealing with a User struct to begin with, so
just check the child struct inside User.superuser?/1 with pattern matching.

auth_active?/1 can check remote users and return true directly.