Roundup provides the ability to manage access to each of a classes
properties (ie. View, Edit, etc.). For properties that users do not have
View permissions for the current value of a property will be displayed
as '[hidden]' in the node journal/history. The problem is that
older/previous values for the same property are not sanitised at all, so
users can view information that they probably should not be able to.

example:
Date                 User     Action  Args
2015-01-12 02:27:11  user1    set     secure_prop: Old Value2 -> [hidden]
2015-01-12 02:26:48  user1    set     secure_prop: Old Value -> Old Value2
2015-01-12 02:26:43  user1    set     secure_prop: Old Value

Ideally the properties that users do not have View access to should
probably not appear in the journal/history at all.

Jerry, I just checked in [462b0f76fce8] to the repo. It should fix
this issue.

I pushed the check into hyperdb.py::Class::history(). It now checks
for View access on the property. If there is no View access, the
journal entry is not shown.  (setting enforceperm = False in the
history call skips the check).

I also pushed the filtering of quiet properties into the hyperdb from
the templating class. (on by default, calling it with skipquiet=False
reports the quiet props).

I had to fix up a few other calls to history to disable the filtering
(e.g. the code that backs the roundup-admin export function).

If you get a chance to try it.