Enable to pop back to where helm-etags-select was last invoked.
Merge pull request #237 from yasuyk/etags-select-enable-to-pop-back

Enable to pop back to where helm-etags-select was last invoked.
* helm-tags.el: Revert previous commit.
* helm-tags.el (helm-etags-default-action): Fix previous pull-request #237, declare `find-tag-marker-ring' and require etags.
* helm-utils.el (helm-walk-directory): Allow skiping subdirs.
(helm-walk-ignore-directories): New.
* helm-apt.el (helm-apt-generic-action): Don't recreate a new term buffer.
* helm-apt.el (helm-apt-cache-show): Use new mode helm-apt-show-mode.
* helm.el (helm-minibuffer-completion-contents): New, replace minibuffer-completion-contents.
(helm-delete-minibuffer-contents): Use it.
* helm-eval.el (helm-eldoc-show-in-eval): Use it
* helm-eval.el (helm-eldoc-show-in-eval): Get rid of `minibuffer-completion-contents'.
* helm-utils.el (helm-find-file-as-root): Issue #240 let-bind non-essential.
* helm-bmkext.el: Add a delete command to addressbook.
* helm-help.el (helm-ff-help-message): Remove obsolete info.
* helm-plugin.el (helm-headline-get-candidates): avoid using flet.
* helm-mode.el (helm-comp-read-get-candidates): Issue #241 Fix wrong-type-argument error in predicate.
* helm-mode.el: Issue #241 Handle commandp predicate as before.
* helm-firefox.el: Issue #243 allow customizing firefox directory location.
(helm-firefox-default-directory): new.
(helm-get-firefox-user-init-dir): Don't hardcode firefox directory location.
* helm.el (with-helm-temp-hook): New macro.
(with-helm-after-update-hook): Use it.
* helm-config.el: Font-lock with-helm-temp-hook.
* helm.el (with-helm-after-update-hook): Add declare form.
* helm-files.el (helm-findutils-transformer): Use helm-boring-file-regexp-list.
(helm-findutils-ignore-boring-files): New.
* helm-files.el (helm-ff-transform-fname-for-completion): Fix weird directory name completion.
(helm-ff-match-fn): removed.