Add new executable to enumerator for wordlist generation

[stevecoward]

This new executable will be a part of enumerator. A separate command (e.g. enumerator-cewl) will utilize cewl and john to fetch words from a user-provided site, mutate it to some degree with john, and write the result to file for the user to use as a password wordlist.

Note: Implementation discussion needed prior to starting.