Renamed ActivityPingback to ActivityPush

Did this for a couple of reasons:

• To avoid confusion with Pingback and all its variants (should have done this a long time ago as per Evan's advise).
• To see if I can evolve this into a simple and generic way to push activities, to avoid having to use two protocol, one for pushing solicited notification (to subscribers via PubSubHubbub) and one for unsolicited notifications (which is what ActivityPush does currently). This is similar to what Pump.io does (replaces PubSubHubbub + Salmon), but I want to see if I can do it without an HTTP based protocol and differing a lot of things to the implementations.

Distributed Mentions

Given the URI-centric approach of Activity Pingback (and Activity Web) I'm leaning towards /username over @username to mention/reply-to users on Converspace. This works very well because it's just a relative URI and lends itself well to the Federated Social Web by allowing you to mention/reply-to someone on another network with simple prefixing: some-other-social-network.com/username or another-social-network.com/users/username.

Inspired by:

• "/ is the new @." - Dave Morin
• Slide #37 of Social Network Supermarkets and How to Defeat Them - Chris Messina

See also:

• Consider using emails instead of URIs for identity