Cleanup parser frontend in preparation for extended permissions

The parser front end is inconsistent about how it handles permissions and rules. This makes extending the permission set and fixing inconsistencies between say file and af_unix rules difficult and prone to failures.

This is a set of work to cleanup the frontend parse handling, and middle semantic checks, dedup, and processing of rules and their permissions. It also is starting to lay the ground work for the parser retaining more information to output better error, and debug messages.

Signed-off-by: John Johansen john.johansen@canonical.com