Experimental arbitrary overlays interface for iedit

`SPC s e` does not select the symbol under point, instead there is no
overlays created and using tab will add overlays 1 character wide

Old `SPC s e` is now on `SPC s E` (to reflect the other bindings like
`SPC s p` and `SPC s P`)

spacemacs/packages.el

@@ -939,7 +939,8 @@ Example: (evil-map visual \"<\" \"<gv\")"
     (define-key evil-iedit-state-map
       (kbd evil-leader/leader) evil-leader--default-map))
 
-  (evil-leader/set-key "se" 'evil-iedit-state/iedit-mode)
+  (evil-leader/set-key "se" 'evil-iedit-state)
+  (evil-leader/set-key "sE" 'evil-iedit-state/iedit-mode)
   (add-to-hooks 'spacemacs/evil-state-lazy-loading '(find-file-hook)))
 
 (defun spacemacs/init-evil-indent-textobject ()
@@ -2401,7 +2402,29 @@ Put (global-hungry-delete-mode) in dotspacemacs/config to enable by default."
   (use-package iedit
     :defer t
     :init
-    (setq iedit-toggle-key-default nil)))
+    (progn
+      (setq iedit-current-symbol-default t
+            iedit-only-at-symbol-boundaries t
+            iedit-toggle-key-default nil))
+    :config
+    (defun iedit-toggle-selection ()
+      "Override default iedit function to be able to add arbitrary overlays.
+
+It will toggle the overlay under point or create an overlay of one character."
+       (interactive)
+       (iedit-barf-if-buffering)
+       (let ((ov (iedit-find-current-occurrence-overlay)))
+         (if ov
+             (iedit-restrict-region (overlay-start ov) (overlay-end ov) t)
+           (save-excursion
+             (push (iedit-make-occurrence-overlay (point) (1+ (point)))
+                   iedit-occurrences-overlays))
+           (setq iedit-mode
+                 (propertize
+                  (concat " Iedit:" (number-to-string
+                                     (length iedit-occurrences-overlays)))
+                  'face 'font-lock-warning-face))
+           (force-mode-line-update))))))
 
 (defun spacemacs/init-indent-guide ()
   (use-package indent-guide