0.18: Iconfont a11y fix (yellowled)

0.17: Adapt backend to 2.x (yellowled)

0.16: Use htmlspecialchars() in the RSS output to prevent XML parsing errors

sidebar 0.13: Filer by event enddate, not starttime

0.15: events lasting more than one day are displayed completely in the calendar
      sidebar plugin instead of showing the start day only (brockhaus)

0.14: earlier versions