* lisp/emacs-lisp/package.el: Fix bug#16733 (again).
(url-http-parse-response, url-http-end-of-headers, url-recreate-url)
(url-http-target-url): Remove unused declarations.
(package-handle-response): Remove.
(package--with-work-buffer): Use url-insert-file-contents and simplify.
(package--download-one-archive): Use current-buffer instead of
dynamic binding of `buffer'.
(describe-package-1): Do not decode readme-string.
* lisp/url/url-handlers.el (url-http-parse-response): Add autoload.
(url-insert-file-contents): Signal file-error in case of HTTP error.