(eldoc-message-commands): Doc fixes.

(eldoc-message-commands): Doc fixes.

(eldoc-message): Make function, not macro.

(eldoc-last-message): New internal variable.
(eldoc-mode): Initialize it to nil.
(eldoc-message): Use it.
(eldoc-print-current-symbol-info): Use it.

(eldoc-pre-command-refresh-echo-area): New function.
(eldoc-mode): Put it on pre-command-hook if in XEmacs or using idle timers
in Emacs.

(eldoc-message-commands-table-size): New constant.
(eldoc-add-command): Use it to initialize eldoc-message-commands.

(eldoc-display-message-no-interference-p): New function.
(eldoc-display-message-p): Use it.

(eldoc-print-fnsym-args, eldoc-print-var-docstring): Arg sym no longer
optional.
Do not initialize arg if nil.

(eldoc-forward-sexp-safe): Function deleted.
(eldoc-beginning-of-sexp): New function.
(eldoc-fnsym-in-current-sexp): Use eldoc-beginning-of-sexp.
Use eldoc-current-symbol to get symbol at point.

(eldoc-function-argstring-from-docstring-method-table): Forge docstrings
for `and', `or', `list', `+', and `-'.

(eldoc-add-command-completions): New function.
(eldoc-add-command): Take list of args.
No longer interactive.

(eldoc-remove-command-completions): New function.
(eldoc-remove-command): Take list of args.
No longer interactive.

top level: Initialize eldoc-message-commands using
eldoc-add-command-completions.