helm-find-files: use C-h and C-l to go up down a directory

Import TheBB configuration into Spacemacs and add `C-S-h` to replace
redefined `C-h` binidng.

Also remove the go up a directory behavior on backspace, now backspace
is a regular backspace.

doc/DOCUMENTATION.org

@@ -99,6 +99,7 @@
        - [[#special-buffers][Special Buffers]]
        - [[#files-manipulations-key-bindings][Files manipulations key bindings]]
        - [[#emacs-and-spacemacs-files][Emacs and Spacemacs files]]
+       - [[#browsing-files-with-helm][Browsing files with Helm]]
      - [[#ido][Ido]]
      - [[#ido-micro-state][Ido micro-state]]
      - [[#neotree-file-tree][NeoTree file tree]]
@@ -1582,6 +1583,19 @@ navigate between =Emacs= and =Spacemacs= specific files.
 | ~SPC f e R~ | resync the dotfile with spacemacs                                    |
 | ~SPC f e v~ | display and copy the spacemacs version                               |
 
+**** Browsing files with Helm
+In =vim= and =hybrid= styles, Spacemacs remap the navigation in Helm find-files
+to keep finger on the home row.
+
+| Key Binding | Description                       |
+|-------------+-----------------------------------|
+| ~C-h~       | go up one level (parent directory |
+| ~C-H~       | describe key (replace ~C-h~)      |
+| ~C-j~       | go to previous candidate          |
+| ~C-k~       | go to next candidate              |
+| ~C-l~       | enter current directory           |
+
+
 *** Ido
 =Spacemacs= displays the =ido= minibuffer vertically thanks to the
 [[https://github.com/gempesaw/ido-vertical-mode.el][ido-vertical-mode]].
@@ -2501,12 +2515,13 @@ setup the key on tabulation:
 *** Helm
 =Spacemacs= add =hjkl= navigation to =helm= buffers:
 
-    | Key Binding | Description         |
-    |-------------+---------------------|
-    | ~C-h~       | go to previous page |
-    | ~C-j~       | go to previous item |
-    | ~C-k~       | go to next item     |
-    | ~C-l~       | go to next page     |
+    | Key Binding | Description                  |
+    |-------------+------------------------------|
+    | ~C-h~       | go to next source            |
+    | ~C-H~       | describe key (replace ~C-h~) |
+    | ~C-j~       | go to previous candidate     |
+    | ~C-k~       | go to next candidate         |
+    | ~C-l~       | same as ~return~             |
 
 ** Emacs Server
 =Spacemacs= starts a server at launch. This server is killed whenever you close

layers/+distribution/spacemacs-base/packages.el

@@ -546,14 +546,6 @@ Removes the automatic guessing of the initial value based on thing at point. "
       ;; helm-locate uses es (from everything on windows, which doesnt like fuzzy)
       (setq helm-locate-fuzzy-match (executable-find "locate"))
 
-      (defun spacemacs/helm-find-files-navigate-back (orig-fun &rest args)
-        )
-      (defadvice helm-ff-delete-char-backward
-          (around spacemacs/helm-find-files-navigate-back activate)
-        (if (= (length helm-pattern) (length (helm-find-files-initial-input)))
-            (helm-find-files-up-one-level 1)
-          ad-do-it))
-
       (defun spacemacs//helm-do-grep-region-or-symbol (&optional targs use-region-or-symbol-p)
         "Version of `helm-do-grep' with a default input."
         (interactive)
@@ -754,10 +746,17 @@ Removes the automatic guessing of the initial value based on thing at point. "
 ARG non nil means that the editing style is `vim'."
         (cond
          (arg
+          ;; better navigation on homerow
+          ;; rebind `describe-key' for convenience
           (define-key helm-map (kbd "C-j") 'helm-next-line)
           (define-key helm-map (kbd "C-k") 'helm-previous-line)
           (define-key helm-map (kbd "C-h") 'helm-next-source)
-          (define-key helm-map (kbd "C-l") 'helm-previous-source))
+          (define-key helm-map (kbd "C-S-h") 'describe-key)
+          (define-key helm-map (kbd "C-l") (kbd "RET"))
+          (dolist (keymap (list helm-find-files-map helm-read-file-map))
+            (define-key keymap (kbd "C-l") 'helm-execute-persistent-action)
+            (define-key keymap (kbd "C-h") 'helm-find-files-up-one-level)
+            (define-key keymap (kbd "C-S-h") 'describe-key)))
          (t
           (define-key helm-map (kbd "C-j") 'helm-execute-persistent-action)
           (define-key helm-map (kbd "C-k") 'helm-delete-minibuffer-contents)