In `wptexturize()`, don't convert C-style hexadecimals to mathematical `×`.

Adds unit tests.

Props harrym, kurtpayne, miqrogroove.
Fixes #19308.


git-svn-id: https://develop.svn.wordpress.org/trunk@28719 602fd350-edb4-49c9-b593-d223f7449a82
In `WP_Comment_Query::get_search_sql()`, don't double-like-escape.

Props miqrogroove.
See #10041.


git-svn-id: https://develop.svn.wordpress.org/trunk@28720 602fd350-edb4-49c9-b593-d223f7449a82