Mainly useful for user export.

`approve_friend_request`, and `deny_friend_request` actions.
Add follow_request_count to the user view.

This was a dirty regex replace which worked on my server

Added tests.

(calling `Instances.set_reachable/1` only if instance had `unreachable_since`,
calling `Instances.set_unreachable/1` only if instance had nil `unreachable_since`).

This reverts merge request !733

that is the only change from nodeinfo 2.0 to 2.1

also this makes the nodeinfo tests use 2.1.json instead of 2.0.json