* lisp/emacs-lisp/package.el (package--alist): New

* lisp/emacs-lisp/package.el (package--alist): New

(package-activate-all): Use it so we only initialize the local part of
package.el (this reduces the impact of bug#24467 and speeds up startup).
(package-installed-p): Use it so it works even if package is not
fully initialized.
(package-delete): Use it so we only initialize the local part of
package.el.