* emacs-lisp/package.el (package-unpack): Remove no-op.

* emacs-lisp/package.el (package-unpack): Remove no-op.
(package--builtins, package--dir): Doc fix.
(package-activate-1, package-activate, package-install)
(package-compute-transaction): Fix error message.
(package-delete): Use delete-directory.  Omit system packages.
(package-initialize): Set package-alist to nil first.
(package-menu-mark-delete, package-menu-mark-install): Don't add
symbols that are inconsistent with the package state.
(package-menu-execute): Perform deletions and installations as
single batch operations.