WP_HTTP: Curl: Handle Redirections in PHP rather than internally in Curl,...

WP_HTTP: Curl: Handle Redirections in PHP rather than internally in Curl, Simplifies code flow between safe_mode On and Off, and works around certain bugs. Props simonwheatley for initial patch. Fixes #20219, Fixes #17490



git-svn-id: https://core.svn.wordpress.org/trunk@20208 1a063a9b-81f0-0310-95a4-ce76da25c4cd