SEC14 — Credentails.set_privileges()

Summary: The documentation states that the force_commit parameter given the value
of false will cause the privileges to be set at a later time. If so,
what does the out parameter "actual_privileges" return?
Is this valid only if force_commit was true and successful?

Also, boolean states a return value. I believe this should be
void, and state that exceptions will be raised with reasons for
failure.

Close Issue 1765: set_privileges