(REG_AUTO): Define.
(value_type): Replace key_type. Use REG_xxx values directly.
Accomodate change throughout.
(longopts): Add --dword, --dword-le, --none, --qword and --hex options.
(opts): Add -d, -D, -n, -Q and -x options.
(types): Array to convert REG_xxx into strings.
(hex): New variable to keep value of --hex option.
(usage): Accomodate new options. Print only the necessary by default.
Only be verbose in case of -h/--help option.
(cmd_list): Use key separator from -K option when printing.
Print value type when verbose option is given. Handle so far not
handled REG_xxx types.
(cmd_set): Avoid SEGV due to missing argument. Handle so far not
handled REG_xxx types.
(cmd_get): Handle --binary option type agnostic. Handle so far not
handled REG_xxx types.
(main): Handle new options.