* lisp/progmodes/prolog.el: Remove old indent; use post-self-insert-hook.

* lisp/progmodes/prolog.el: Remove old indent; use post-self-insert-hook.
(prolog-align-comments-flag, prolog-indent-mline-comments-flag)
(prolog-object-end-to-0-flag, prolog-electric-newline-flag)
(prolog-electric-tab-flag, prolog-use-prolog-tokenizer-flag):
Remove vars, they do not apply any more.
(prolog-mode-abbrev-table): Remove redundant declaration.
(prolog-upper-case-string, prolog-lower-case-string): Remove.
(prolog-use-smie): Remove.
(prolog-smie-rules): Add indentation rule for the if-then-else layout
supported by prolog-electric-if-then-else-flag.
(prolog-mode-variables, prolog-menu): Use setq-local.
(prolog-mode-keybindings-edit): Don't rebind M-C-p and M-C-n.
Remove binding to `Backspace' since this key doesn't exist anyway.
Remove bindings for electric self-inserting keys.
(prog-mode): Assume it's defined.
(prolog-post-self-insert): New function.
(prolog-mode): Use it.
(prolog-indent-line, prolog-indent-level)
(prolog-find-indent-of-matching-paren)
(prolog-indentation-level-of-line, prolog-goto-comment-column)
(prolog-paren-is-the-first-on-line-p, prolog-region-paren-balance)
(prolog-goto-next-paren, prolog-in-string-or-comment)
(prolog-tokenize, prolog-inside-mline-comment)
(prolog-find-start-of-mline-comment): Remove functions.
(prolog-find-unmatched-paren, prolog-clause-end)
(prolog-guess-fill-prefix, prolog-get-predspec): Use syntax-ppss.
(prolog-electric--if-then-else): Rename from
prolog-insert-spaces-after-paren; use prolog-electric-if-then-else-flag.
(prolog-tokenize-searchkey): Remove const.
(prolog-clause-info): Use forward-sexp.
(prolog-forward-list, prolog-backward-list, prolog-electric-delete)
(prolog-electric-if-then-else): Remove commands.
(prolog-electric--colon): Rename from prolog-electric-colon; adapt it
for use in post-self-insert-hook.
(prolog-electric--dash): Rename from prolog-electric-dash; adapt it
for use in post-self-insert-hook.
(prolog-electric--dot): Rename from prolog-electric-dot; adapt it
for use in post-self-insert-hook.
(prolog-electric--underscore): Rename from prolog-electric--underscore;
adapt it for use in post-self-insert-hook.