uCON64 Code (SVN)

- Extended --hex, --bit, --code and --print to also accept an optional end
offset.
- Updated dumper() to also align the ASCII column for --bit and --code.
Slightly simplified the alignment code for --hex.
- Corrected comment generated by --code.
- Changed type of st_ucon64_t.range_start from off_t to int.
- Fixed ucon64_file_handler() for large files (> 2GB) on Windows.
- Fixed potential buffer overflow in ucon64_switches().
- Replaced call to sscanf() for --range with a more elaborate implementation
with better error handling.