Implement outputting normalized audit event data

[spbnick]

Audit is introducing a new feature: "normalizer". Essentially normalizer
extracts basic semantic information from the event, such as subject, action,
object, and result. This allows formatting much more human-readable messages
out of often cryptic audit events. See the announcement at
https://www.redhat.com/archives/linux-audit/2017-February/msg00060.html

Add that data to aushape output as an option.