* ses.el (macroexp): add require for this package, so that function
`ses--cell gets macroexp-quote.
(ses--cell): makes formula a macroexp-quote of value when formula
is nil. The rationale of this changr is to allow in the future
shorter SES files, e.g. we could have only `(ses-cell A1 1.0)'
instead of `(ses-cell A1 1.0 1.0 nil REFLIST)'. In such a case
reference list REFLIST would be re-computed after load --- thus
trading off load time against file size.

* emacs-lisp/package.el (package--alist-to-plist-args): use
macroexp-quote instead of a lambda expression which has the same
content as macroexp-quote.
(macroexp): add require for this package, so that function
`package--alist-to-plist-args' gets macroexp-quote.

* emacs-lisp/macroexp.el (macroexp-quote): new defun.