Unit Tests

- Removed diagnostic output that is no longer needed.
Date

- Removed ::isRelativeDate and instead used namedDates. Which is better.
Date

- Uses mk_wcwidth to calculate the printed width of a character in a date
  format that is not recognized, instead of simply assuming '1'.
Dates

- Fixed problem with eoy, where is was YYYY-12-31T00:00:00, which is
  24 hours earlier than actual eoy. Other 'eo*' names were also wrong.
  So much for unit tests.
Task

- Improved implementation of is_duemonth and is_dueweek.