TODO

Possible ways to enhance the results:

* Look at the most common characters of all the possible words
  remaining, and and order the words based on those containing the
  highest number of the most popular characters remaining. Focus on
  ruling those out first, instead of simply focusing on vowels without
  any result analysis. The intent is to maximise the number of words
  we can rule out for a given attempt.

* Add an option to test characters with a known-bad submission. ie.
  For when where there are too many possible answers, add a switch to narrow
  results down by submission of a word that's known to be invalid. eg. _olar
  might start with m, p, s or v which may require 4 additional attempts, so
  finding a 5 character word with most of those possible characters might be
  faster.