* packages/cl-lib: New package.
Add cl-letf and cl-labels.
* cl-lib.el: Try and patch things up in case we're hiding the real cl-lib.
* cl-lib.el (cl-labels): Demote error to message and improve it.
* cl-lib.el: Resolve conflicts with old internal definitions (bug#16353).
(dolist fun): Don't skip definitions silently.
(define-setf-expander): Remove, not in cl-lib.
(cl-position, cl-delete-duplicates): Add advice to distinguish the use case.
(cl-member): Override old definition.
Fixes: debbugs:16671

* cl-lib.el (cl-position, cl-delete-duplicate): Don't advise if >=24.3.
(load-path): Try to make sure we're at the end.