(struct File_spec, reopen_inaccessible_files, count_lines,

(struct File_spec, reopen_inaccessible_files, count_lines,
forever, from_start, print_headers, have_read_stdin, valid_file_spec,
write_header, file_lines, pipe_lines, pipe_bytes, recheck,
tail_forever, tail_bytes, tail_lines, tail, tail_file,
parse_obsolescent_option, parse_options, main):
Use bool for booleans.
(struct File_spec, max_n_unchanged_stats_between_opens,
parse_options): Use uintmax_t, not unsigned int or unsigned long int,
for state counters.
(tail_bytes, tail_lines): Redo test of return value (-1, 0, 1) to
make it a bit clearer.