Remove some `toggle-read-only' warnings.

* lisp/bs.el (bs-toggle-readonly): Call `toggle-read-only' interactively.

* lisp/descr-text.el (describe-char):
  lisp/progmodes/python.el (python-describe-symbol):
  Don't call `toggle-read-only', set `buffer-read-only'.
Mention in "C-u C-x =" display how to insert the character w/o input methods.

 lisp/descr-text.el (describe-char): Mention how to insert the
 character, if the current input method doesn't support it.
 See the discussion in this thread for the details:
 http://lists.gnu.org/archive/html/emacs-devel/2012-05/msg00533.html.
* lisp/descr-text.el (describe-char): Fix format args.
* descr-text.el (describe-char): Don't insert extra newlines.
* descr-text.el (describe-char): Put the overlays over the
"displayed as" character.
Make C-u C-x = report on empty overlays at point.

* lisp/descr-text.el (describe-text-properties-1): Use overlays-in to
report on empty overlays.
Fix bug #11964 with crashes inside internal-char-font on non-GUI frames.

 lips/descr-text.el (describe-char-padded-string): Call
 internal-char-font only on GUI frames.
Update copyright notices for 2013.