- This adds a new crate, `tor-geoip`, which can parse and perform
lookups in the GeoIP database C-tor already uses (generated by a
maintenance utility in the C-tor codebase).
- We embed a copy of C-tor's databases with the crate and use
`include_str!` to ship them with the binary, bloating its size
somewhat.
- This does, however, solve the problem of figuring out how to
distribute these.
- The plan is to gate this functionality behind a feature flag anyway,
so the cost should be nil unless explicitly opted into.
Part of tpo/core/onionmasq#47.