Switch to using HTTPS connections for Plugin and Theme API requests when SSL is available. See #18577

Built from https://develop.svn.wordpress.org/trunk@25308


git-svn-id: http://core.svn.wordpress.org/trunk@25270 1a063a9b-81f0-0310-95a4-ce76da25c4cd
WP_HTTP: Correct the @since, and, @deprecated PHPDoc tags to reflect the class history. See #25007

Built from https://develop.svn.wordpress.org/trunk@25309


git-svn-id: http://core.svn.wordpress.org/trunk@25271 1a063a9b-81f0-0310-95a4-ce76da25c4cd