* helm-help.el (helm-help-message): Update.
Merge branch 'master' of github.com:emacs-helm/helm

Conflicts:
	helm-help.el
Merge (conflict).
* helm-grep.el: Fix recursive `helm-do-grep' with empty extensions (#578).
(helm-do-grep-1): Don't call `helm-grep-read-ack-type' when using grep and exts is empty string.
(helm-grep-get-file-extensions): Return nil when user press C-RET.
* helm.el (helm-kill-selection-and-quit): Fix docstring.