Inhibit quote autopairing more frequently

Inhibit quote autopairing more frequently

Backported from trunk 2014-04-02T09:59:06Z!joaotavora@gmail.com

* lisp/elec-pair.el (electric-pair-inhibit-if-helps-balance): Inhibit
quote pairing if point-max is inside an unterminated string.
(electric-pair--looking-at-unterminated-string-p):
Delete.
(electric-pair--in-unterminated-string-p): New function.

* test/automated/electric-tests.el (inhibit-if-strings-mismatched):
New test, change from `inhibit-only-of-next-is-mismatched'.