* lisp/emacs-lisp/smie.el: Simplify the smie-rules-function return values.

* lisp/emacs-lisp/smie.el: Simplify the smie-rules-function return values.
(smie-precs->prec2): Rename from smie-precs-precedence-table.
(smie-bnf->prec2): Rename from smie-bnf-precedence-table.
(smie-prec2->grammar): Rename from smie-prec2-levels.
(smie-grammar): Rename from smie-op-levels.
(smie-indent--hanging-p): Rename from smie-hanging-p.
(smie-rule-hanging-p): New alias.
(smie-indent--bolp): Rename from smie-bolp.
(smie-indent--hanging-p): New alias.
(smie--token): New dynamically bound variable.
(smie-indent--parent): New function.
(smie-rule-parent-p): Use it; rename from smie-parent-p.
(smie-rule-next-p): Rename from smie-next-p.
(smie-rule-prev-p): Rename from smie-prev-p.
(smie-rule-sibling-p, smie-rule-parent)
(smie-indent--separator-outdent, smie-rule-separator): New functions.
(smie-rule-separator-outdent): New var.
(smie-indent--rule): Merge with smie-indent--column.
(smie-indent-forward-token, smie-indent-backward-token):
Also recognize close parens.
(smie-indent-keyword): Don't use smie-indent--column any more.
(smie-indent-after-keyword): Ignore closers by default.
(smie-indent-line): Use with-demoted-errors.
* lisp/progmodes/octave-mod.el (octave-smie-grammar):
Rename from octave-smie-op-levels.
(octave-smie-rules): Adjust to new behavior.
* lisp/progmodes/prolog.el (prolog-smie-grammar):
Rename from prolog-smie-op-levels.