* lisp/ses.el (ses--row, ses--col): New dyn-scoped vars, to replace row&col.

* lisp/ses.el (ses--row, ses--col): New dyn-scoped vars, to replace row&col.
(ses-center, ses-center-span): Use them.
(ses-print-cell): Bind them while calling the printer.
(row, col, maxrow, maxcol): Don't declare as dynamically scoped.
(ses-dorange): Revert last change.
(ses-calculate-cell): Don't bind row&col dynamically while evaluating
the formula.
(ses-set-cell): Avoid `eval'.
(ses--time-check): Rename it from ses-time-check and turn it into
a macro.

Fixes: debbugs:18191