* autoconf.sh: Don't show obsolete options on "--help". Report

    * autoconf.sh: Don't show obsolete options on "--help". Report
        obsolete options to stderr. Adjust list of options. Correct
        processing of options. Process options with values separated by
        "=" first, so that abbreviations work. Don't accept "=" with
        short options.
        * autoheader.sh: Likewise.
        * autoreconf.sh: Likewise.
        * autoupdate.sh: Likewise.
        * ifnames.sh: There is no "--verbose" option.
        * doc/autoconf.texi: Option "-A" requires an argument.
        (autoreconf Invocation): Document "--install", "--symlink",
        "--m4dir" and the options passed to Automake.