Remove useless leading * in defcustom docstrings.

Remove useless leading * in defcustom docstrings.
(save-completions-file-name): Use ~/.emacs.d if available.
(completion-standard-syntax-table): Rename from
cmpl-standard-syntax-table and fold initialization into declaration,
thus removing cmpl-make-standard-completion-syntax-table.
(completion-lisp-syntax-table, completion-c-syntax-table)
(completion-fortran-syntax-table, completion-c-def-syntax-table): Idem.
(cmpl-saved-syntax, cmpl-saved-point): Remove.
(symbol-under-point, symbol-before-point)
(symbol-under-or-before-point, symbol-before-point-for-complete)
(add-completions-from-c-buffer): Use with-syntax-table.
(make-completion): Don't return a list of completion entries.
Update callers.
(cmpl-prefix-entry-head, cmpl-prefix-entry-tail): Use defalias.
(completion-initialize): Rename from initialize-completions.
(completion-find-file-hook): Rename from cmpl-find-file-hook.
(kill-emacs-save-completions): Collect stats here.
(save-completions-to-file, load-completions-from-file):
Use with-current-buffer.
(completion-def-wrapper): Rename from def-completion-wrapper.  Make it
into a function.  Move all calls to toplevel.
(completion-lisp-mode-hook): New fun.
(completion-c-mode-hook, completion-setup-fortran-mode):
Set the syntax-table here.  Use local-set-key.
(completion-saved-bindings): New var.
(dynamic-completion-mode): Make it into a proper minor mode.
(load-completions-from-file): Remove unused var `num-uses'.