1. Randomize the last 3 characters of the internal code to generate a unique
   internal code.
2. Attempt to skip sub-directory names when generating long/short names from
   imported path, if no sub-dirs are in the path, then just right-justify the
   truncated path - trying to generate meaninful long/short names from long
   paths.
3. Do not allow duplicate paths to be imported into the same library.
4. Skip (do not import) directory entries that are > 63 chars in length.
5. Stop importing if/when total dirs >= MAX_DIRS (65534).