Add toggles for tool bar and menu bar

Resolves #361

doc/DOCUMENTATION.md

@@ -696,6 +696,8 @@ Some UI indicators can be toggled on and off (toggles start with `t`):
 <kbd>SPC t M</kbd>    | toggle frame maximize
 <kbd>SPC t n</kbd>    | show the absolute line numbers
 <kbd>SPC t t</kbd>    | toggle frame transparency
+<kbd>SPC t T</kbd>    | toggle tool bar
+<kbd>SPC t U</kbd>    | toggle menu bar
 
 ## Mode-line
 

spacemacs/funcs.el

@@ -876,6 +876,21 @@ If ASCII si not provided then UNICODE is used instead."
     (evil-end-of-line)
     (eval-last-sexp nil)))
 
+(defun spacemacs/toggle-tool-bar ()
+  "Toggle the tool bar.
+It has no effect in a terminal."
+  (interactive)
+  (when window-system
+    (tool-bar-mode (if tool-bar-mode -1 1))))
+
+(defun spacemacs/toggle-menu-bar ()
+  "Toggle the menu bar.
+It has no effect in a terminal if the Emacs version is < `24.4'."
+  (interactive)
+  (when (or window-system
+            (version<= "24.3.1" emacs-version))
+    (menu-bar-mode (if menu-bar-mode -1 1))))
+
 (defun spacemacs/open-in-external-app ()
   "Open current file in external application."
   (interactive)

spacemacs/keybindings.el

@@ -137,6 +137,8 @@
   "tM" 'toggle-frame-maximized
   "tn" 'global-linum-mode
   "tt" 'toggle-transparency
+  "tT" 'spacemacs/toggle-tool-bar
+  "tU" 'spacemacs/toggle-menu-bar
   "t SPC" 'whitespace-mode)
 ;; quit -----------------------------------------------------------------------
 (evil-leader/set-key