Wip/discordian

All tests passing (except `with(ERA)`, which is fixed by the changes in trunk).
St. Tib's Day indicated by month/day-of-month/day-of-week/week-of-month = 0
ALIGNED_WEEK_OF_YEAR for St. Tib's Day is 12, because conceptually this seems bound to day-of-year.  This means that `with(ALIGNED_WEEK_OF_YEAR)` can be used to move off of St. Tib's Day, whereas none of those other fields can.  
Getting to St. Tib's Day can be accomplished via construction (ie `DiscordianDate.of(year, 0, 0)`), `plus(DAYS, n)`, or `with(MONTH_OF_YEAR, 0)`.