* helm-mode.el: Issue #391 prefix some internal functions with helm--.
Make clear that helm--completing-read-default and helm--generic-read-file-name
should not be used by users.
* helm.el: Issue #387 helm-next/previous-line move to beg or end of source when on top or bottom.
(helm-move-to-line-cycle-in-source): new.
(helm-move--previous-multi-line-fn): new.
(helm-move--previous-line-fn): Do it.
(helm-move--next-multi-line-fn): new.
(helm-move--next-line-fn): Do it.
(helm-move--beginning-of-source,
helm-move--beginning-of-source): new.
* helm.el (helm-next-line, helm-previous-line): Ensure helm-move-to-line-cycle-in-source is used only in interactive calls.
* helm-ring.el: Fix global mark ring.
(helm-global-mark-ring-get-candidates): Fix.