scslab/lio — pull request #2 by deian (2012-02-27 19:33:42+00:00)
Title: fix bug in withPrivileges, add dropPrivileges

* withPrivileges no longer mconcat's with underlying privileges, so withPriviliges noPrivs is an action with no underlying priviliges, etc.

* dropPrivilges allows a computation to drop all underlying privileges. We do not expose setPrivileges as it is more likely to be used in an unsafe fashion.