* Bug: "none" matching nothing (formerly it matched everything).
* Bug: Inverted year ranges (e.g. 2015-2010) are now equivalent to standard
formatted ranges.
* Bug: "12pm" and "12am" are handled correctly for hours now.
* Bug: Empty ranges (e.g. "wk {}") are no longer an error, but they never
match.
* Bug: The week number calculation is fixed:
- Previously, the days 1-7 would be the first week, 8-14 would be the
second week, etc.
- Now, it counts the number of Sunday's that have passed.