Improve the ACL dumping to support names

The previous version dumps Principal ID's pointing
to ACLEquivalence groups. These are quite useless when
there are removed users (ie. rt-shredder removed some users)
or when you skip certain users (limit-privileged-users).

This version should dump ACLs using users' Name,
groups' Name and global Rolegroups' Name attributes.
Merge commit '5d29acb' into 4.0-kai
Add an option to skip disabled objects