* lisp/ido.el: Doc fix.

* lisp/ido.el (ido-fractionp):
(ido-cache-ftp-work-directory-time, ido-max-prospects, ido-mode)
(ido-max-file-prompt-width, ido-unc-hosts-cache)
(ido-max-directory-size, ido-max-dir-file-cache)
(ido-decorations): Doc fix.
doc/lispref/buffers.texi: Add documentation for ido-record-command(s).

* lisp/ido.el (ido-record-command): Add doc string.
* lisp/ido.el (ido-completion-help): Fix up compiler warning.