Inline documentation for hooks in wp-includes/comment.php.

comment.php, a.k.a. "lots 'o hooks".

Props swissspidy for the initial patch. Props danieldudzic, kpdesign, and DrewAPicture.
Fixes #25522.


git-svn-id: https://develop.svn.wordpress.org/trunk@26491 602fd350-edb4-49c9-b593-d223f7449a82