Avoid an empty href attribute in paginate_links(). Add unit tests.

props obenland, Nessworthy.
fixes #24606.
Built from https://develop.svn.wordpress.org/trunk@28671


git-svn-id: http://core.svn.wordpress.org/trunk@28489 1a063a9b-81f0-0310-95a4-ce76da25c4cd
wp_insert_comment() and wp_new_comment() should check if the comment was successfully inserted into the database.

props pento.
fixes #28254.
Built from https://develop.svn.wordpress.org/trunk@28672


git-svn-id: http://core.svn.wordpress.org/trunk@28490 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Remove redundant 'Visit author homepage' title attributes for plugins and themes.

props joedolson.
fixes #26554.
Built from https://develop.svn.wordpress.org/trunk@28673


git-svn-id: http://core.svn.wordpress.org/trunk@28491 1a063a9b-81f0-0310-95a4-ce76da25c4cd