Allow the single quotes, apostrophes, and primes in wptexturize() to be...

Allow the single quotes, apostrophes, and primes in wptexturize() to be translated. Allows replacements to be disabled by translating them back to " and '. fixes #19602.

git-svn-id: https://core.svn.wordpress.org/trunk@19795 1a063a9b-81f0-0310-95a4-ce76da25c4cd