Add 'wp_title_parts' filter to wp_title().

props aaroncampbell, obenland.
fixes #17877.
Built from https://develop.svn.wordpress.org/trunk@28669


git-svn-id: http://core.svn.wordpress.org/trunk@28487 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add a filter to human_time_diff().

props slimndap.
fixes #27271.
Built from https://develop.svn.wordpress.org/trunk@28670


git-svn-id: http://core.svn.wordpress.org/trunk@28488 1a063a9b-81f0-0310-95a4-ce76da25c4cd