• Added explicit check for valid hours if AM/PM is specified in parser.
  (gh pr #22, issue #21)
• Fix bug in rrule introduced in 2.4.0 where byweekday parameter was not
  handled properly. (gh pr #35, issue #34)
• Fix error where parser allowed some invalid dates, overwriting existing hours
  with the last 2-digit number in the string. (gh pr #32, issue #31)
• Fix and add test for Python 2.x compatibility with boolean checking of
  relativedelta objects. Implemented by @nimasmi (gh pr #43) and Cédric Krier
  (lp: 1035038)
• Replaced parse() calls with explicit datetime objects in unit tests unrelated
  to parser. (gh pr #36)
• Changed private _byxxx from sets to sorted tuples and fixed one currently
  unreachable bug in _construct_byset. (gh pr #54)
• Additional documentation for parser (gh pr #29, #33, #41) and rrule.
• Formatting fixes to documentation of rrule and README.rst.
• Updated zoneinfo to 2015a.