• Fix an issue with relativedelta and freezegun (lp:1374022)
• Fix tzinfo in windows for timezones without dst (lp:1010050, gh #2)
• Ignore missing timezones in windows like in POSIX
• Fix minimal version requirement for six (gh #6)
• Many rrule changes and fixes by @pganssle (gh pull requests #13 #14 #17),
  including defusing some infinite loops (gh #4)