(savehist-history-variables): Remove.
(savehist-save-minibuffer-history, savehist-additional-variables)
(savehist-minibuffer-history-variables): New vars.
(savehist-save): Use them.
(savehist-uninstall, savehist-minibuffer-hook): New funs.
(savehist-install): New fun, extracted from savehist-load.
(savehist-load): Use them.
(savehist-xemacs): Remove.
(savehist-coding-system): Use utf-8 if available, regardless of religion.
(savehist-no-conversion): Use (featurep 'xemacs).
(savehist-load): Check existence of start-itimer rather than XEmacs.
Use an idle timer.
(savehist-process-for-saving): Replace use of CL funs `subseq' and
`delete-if-not'.
(savehist-last-checksum, savehist-no-conversion): New vars.
(savehist-autosave, savehist-process-for-saving, savehist-printable): New funs.
(savehist-load, savehist-save): Use them.
(savehist-delimit): Remove.