Add a pre_set_theme_mod_$name filter to set_theme_mod().

This is modeled after pre_update_option_$option in update_option() and pre_set_transient_$transient in set_transient().

props obenland.
fixes #14721.

Built from https://develop.svn.wordpress.org/trunk@27393


git-svn-id: http://core.svn.wordpress.org/trunk@27241 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Bail early from shortcode functions if no delimiter is present.

This is a significant performance improvement for processing content without shortcodes, and only the slightest hit when content contains shortcodes (which must then undergo processing anyway). Performance results on the ticket.

props TobiasBg.
fixes #23855.

Built from https://develop.svn.wordpress.org/trunk@27394


git-svn-id: http://core.svn.wordpress.org/trunk@27242 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add has_password and post_password query variables to WP_Query.

 * has_password true means posts with passwords, false means posts without.
 * post_password can query for posts with a particular password.

props wonderboymusic, robmiller.
fixes #20308.

Built from https://develop.svn.wordpress.org/trunk@27395


git-svn-id: http://core.svn.wordpress.org/trunk@27243 1a063a9b-81f0-0310-95a4-ce76da25c4cd