* doc/bison.texinfo (Debugging): Split into...

* doc/bison.texinfo (Debugging): Split into...
(Tracing): this new section, its former contents, and...
(Understanding): this new section.
* src/getargs.h, src/getargs.c (verbose_flag): Remove, replaced
by...
(report_flag): this.
Adjust all dependencies.
(report_args, report_types, report_argmatch): New.
(usage, getargs): Report/support -r, --report.
* src/options.h
(struct option_table_struct): Rename as..,
(struct option_table_s): this.
Rename the `set_flag' member to `flag' to match with getopt_long's
struct.
* src/options.c (option_table): Split verbose into an entry for
%verbose, and another for --verbose.
Support --report/-r, so remove -r from the obsolete --raw.
* src/print.c: Attach full item sets and lookaheads reports to
report_flag instead of trace_flag.
* lib/argmatch.h, lib/argmatch.c: New, from Fileutils 4.1.