[OJS.de - OA-S I - ap4: event logging hook] Implement event logging hook.
[OJS.de - OA-S I - ap5: event storage, SALT] Implement event storage, SALT management and IP hashing.
[PKP bugs] Add request to template manager calls in issue handler.
[OJS.de - OA-S I - ap6: opt-out and privacy info] implement opt-out and privacy info.