Experiment with counting views (no displaying yet)

[GarboMuffin]

This is only the counting. We'll display them later, once we're somewhat confident in the data.

• A new backend service for view counting: windchimes
• To prevent one person submitting thousands of fake views in a very short time, there are some anti-abuse mechanisms. They're based on a hash of a combination of at least IP + a random frequently-changing salt so that user data doesn't stay in memory longer than needed.
• Once views are committed, all that gets stored is a total count and a daily count. Impossible to tie back to an individual.
• Views through embeds are counted separately internally. Later on can decide how to display that.
• View counting opt-out available in the privacy policy page