New minor mode Electric Quote

New minor mode Electric Quote

This lets you easily insert quotes ‘like this’ by typing
quotes `like this', and similarly you can easily insert
quotes “like this” by typing quotes ``like this'' (Bug#20545).
* doc/emacs/basic.texi (Inserting Text):
* doc/emacs/modes.texi (Minor Modes):
* etc/NEWS: Document it.
* doc/emacs/text.texi (Quotation Marks): New section.
* lisp/electric.el (electric-quote-comment)
(electric-quote-string, electric-quote-paragraph):
New custom vars.
(electric--insertable-p)
(electric-quote-post-self-insert-function): New functions.
(electric-quote-mode, electric-quote-local-mode): New minor modes.
* lisp/progmodes/elisp-mode.el (emacs-lisp-mode):
Add curved single quotes to electric-pair-text-pairs.
Set electric-quote-string in this buffer.