(custom-initialize-after-file): New function

Some global minor modes require initialization.  Those that are preloaded
currently abuse `custom-initialize-delay` for that, but it's suboptimal
and doesn't help those that aren't preloaded.
So introduce a new function to fill that need.
While at it, make `define-globalized-minor-mode` use it
automatically when useful.

* lisp/custom.el (custom-initialize-after-file-load): New function.
* lisp/tooltip.el (tooltip-mode):
* lisp/paren.el (show-paren-mode):
* lisp/rfn-eshadow.el (file-name-shadow-mode):
* lisp/epa-hook.el (auto-encryption-mode):
* lisp/minibuffer.el (minibuffer-regexp-mode, minibuffer-nonselected-mode):
* lisp/electric.el (electric-indent-mode): Use it instead of
`custom-initialize-delay` since the value does not depend on the
runtime context.
(electric-quote-mode): Don't use `custom-initialize-delay` since
the default value is nil anyway.

* lisp/emacs-lisp/easy-mmode.el (define-globalized-minor-mode):
Automatically add `:initialize` if needed.
* lisp/emacs-lisp/eldoc.el (global-eldoc-mode): Remove `:initialize`,
now provided automatically.

* doc/lispref/customize.texi (Variable Definitions):
* doc/lispref/modes.texi (Defining Minor Modes): Document and Suggest
`custom-initialize-after-file-load` instead of `custom-initialize-delay`.

lisp/emacs-lisp/eldoc.el

@@ -238,7 +238,6 @@ expression point is on." :lighter eldoc-minor-mode-string
 
 ;;;###autoload
 (define-globalized-minor-mode global-eldoc-mode eldoc-mode turn-on-eldoc-mode
-  :initialize 'custom-initialize-delay
   :init-value t
   ;; For `read--expression', the usual global mode mechanism of
   ;; `change-major-mode-hook' runs in the minibuffer before