Clarified some namespaces for functions used inside `with-policy' and friends

Namely, `eql' wasn't referred to correctly (it now is prepended by the proper `common-lisp:' namespace).
Added a file for default, globally valid policies for usage in other modules

In the `default-policies', policies for use in other modules reside. Right now, this is just a "simple" timeout policy which will trigger a timeout signal after a certain duration of seconds has passed (if the body code hasn't finished by then).