Sync with Nodeca Core.

- Add full-weight SSL support.
- Add support of frontend proxy servers. (`forwarded` bind option)
- Add `url_to` helper.
- Add support of http/https switching to navigate.js
- Architecture cleanup. Drop `fullUrl`, `pathname`, `cookies`, and `sid`
  custom variables from original `req` object.
- Improve error messages on YAML syntax errors in configs.
- Correct hook priorities.
- Refactor `cookies` hook.
- Fix migration apply ordering.
- Write "[empty]" as server method in RPC logger if no method.