`pp-to-string' modified to be able to format text with newlines.
(pp-to-string): Move the buffer-formatting part of the code to
`pp-buffer'. Call `pp-buffer'.
* facemenu.el (describe-text-done): New function.
(describe-text-mode-map): New variable.
(describe-text-mode-hook): New option.
(describe-text-mode): New function.
(describe-text-widget): New function.
(describe-text-sexp): New function.
(describe-text-properties): New function.
(describe-text-category): New command.
(describe-text-at): New command.
(facemenu-menu): Replace `list-text-properties-at' with
`describe-text-at' in the menu.
* wid-edit.el (widgetp): New function.
* wid-edit.el (widget-keymap, widget-insert, widget-setup):
Autoloaded.
* emacs-lisp/pp.el (pp-to-string): Autoloaded.
* wid-browse.el: Removed version and x-url keywords.