* helm-buffers.el: Add fuzzy searching matching.
(helm-buffers-fuzzy-matching): New option.
(helm-buffer--match-pattern): Use helm--mapconcat-candidate.
* helm-files.el: Remove helm-ff-mapconcat-candidate and move to helm-utils.
* helm-utils.el (helm--mapconcat-candidate): New renamed from helm-ff-mapconcat-candidate.