bug#7611: 23.2; info-xref.el v.3

[Kevin Ryde]

2011-01-07  Kevin Ryde  <user42@zip.com.au>

        * info-xref.el: Version 3.
        (info-xref-check, info-xref-check-all): Commentary details moved
        into docstrings for better visibility.

        Use compilation-mode for the results buffer.
        (info-xref-output, info-xref-output-error, info-xref-with-output)
        (info-xref-filename, info-xref-in-progress):
        New internals for this.
        (info-xref-check-list, info-xref-check-buffer)
        (info-xref-check-all-custom): Use those.
        (info-xref-output-buffer): Renamed from info-xref-results-buffer.
        (info-xref-output-heading): Renamed from info-xref-filename-heading.
        (info-xref-good, info-xref-bad, info-xref-xfile-alist)
        (info-xref-filename-heading): Moved to output managing section.

        (info-xref-docstrings): New command checking "Info node `(foo)Bar'"
        (info-xref-lock-file-p, info-xref-with-file): New helpers for it.
        (info-xref-subfile-p): Moved to generic section with those two.

        (info-xref-check-node): New function split from
        info-xref-check-buffer, shared by info-xref-docstrings.
        (info-xref-goto-node-p): Moved to a checking section with that func.

        (info-xref-unavail): New counter.
        (info-xref-check-node): Use it.
        (info-xref-with-output): Show count of unavailables at end of output.

        (info-xref-all-info-files): Exclude ".*" dotfiles.  Ignore broken
        symlinks.  Exclude .texi files.  Exclude Emacs backup files.

        (info-xref-check-all-custom): Fix quietening viper-mode and
        gnus-registry-install -- must use setq not let so as not to unbind
        after load.