http message/request fluent interface removal

Discussion/reference at:
 - https://groups.google.com/d/msg/php-fig/qXktLjkyLd4/Z09vW7jQWAoJ
 - https://groups.google.com/d/msg/php-fig/qXktLjkyLd4/FoNiKjoVjYUJ
 - http://ocramius.github.io/blog/fluent-interfaces-are-evil/