Include "dirname.h".

Include "dirname.h".
(outbase): Now a global var.
(outfile_end): Remove.
(suffix_length): New var.
(shortopts, longopts, main): Add -a or --suffix-length.
(next_file_name): Implement -a.  Do not extend the suffix length.
Check for file names that are too long.
(main): Move outfile initialization to next_file_name.

(shortopts): Remove -v (a typo).