Implement %z for the internal implementation of strptime(). Unfortunately this doesn't get picked up everywhere, so there are no tests for it (yet - patches welcome).
Fix for major bug in add_months() using negative months which were multiples of 12. Also affected add_years() with negative years.
Fix for object creation bug in get_epochs which called new from object but that wasn't supported in the new() code.
Added docs about the weakness of using epoch seconds internally and suggested alternatives.