r12746: An initial version of the kludge_acls module.

r12746: An initial version of the kludge_acls module.

This should be replaced with real ACLs, which tridge is working on.
In the meantime, the rules are very simple:

- SYSTEM and Administrators can read all.

- Users and anonymous cannot read passwords, can read everything else

- list of 'password' attributes is hard-coded

Most of the difficult work in this was fighting with the C/js
interface to add a system_session() all, as it still doesn't get on
with me :-)

Andrew Bartlett
(This used to be commit be9d0cae8989429ef47a713d8f0a82f12966fc78)