* helm-files.el (helm-find-file-or-marked): Attempt to fix #546, when epg is prompting for password.
* helm-files.el: Fix again #546 when epg is prompting for password.
* helm-utils.el (helm-quit-and-execute-action): No need to use helm-maybe-exit-minibuffer here.
This may lead to infloop.
* helm.el (helm-this-command): Add `helm-confirm-and-exit-minibuffer'.
* helm-utils.el (helm-goto-line-before-hook): Add `helm-save-current-pos-to-mark-ring' by default (#548).
* helm-utils.el: Fix trailing white space.
* helm-regexp.el (helm-moccur-save-results-1): Removed, no more needed.
* helm-utils.el (helm-find-many-files): Fix [display not ready] issue with epg here too (#549).
* helm-files.el (helm-ff-kill-or-find-buffer-fname): Same let-bind `helm--reading-passwd-or-string'.
* helm.el (helm--follow-action): Go to next/previous line if previous commmand is persistent-action.
* helm-regexp.el: No need to have a specific function for nth1 persistent.
* helm-grep.el: Same.
* helm-files.el (helm-find-files-eshell-command-on-file-1): Fix for url's.
* helm-buffers.el (helm-source-buffer-not-found): Use intern-soft.
* helm-mode.el (helm-cr-default-transformer): Unquote candidate only for comparing (#551).
Move `helm-mode-line-string' to helm.el (#554).
* helm-buffers.el (helm-buffer--match-pattern): Disable fuzzy matching when pattern starts with "^".
* helm-help.el: Update buffers doc.
Update "Advanced Usage"
Merge pull request #552 from tuhdo/master

Update "Advanced Usage"
* helm-buffers.el (helm-buffers-mark-similar-buffers): New, bind it.
* helm-help.el: Update buffers doc.