Rainlendar 2.11 Beta 121

* Changes:
- Added support for CalDAV.
- Updated the icons in the options dialog.
- Changed the numeric edit controls to spin controls in the event and task editors.
- Added large version of the calendar window to the Shadow4 skin.
- New Google tasks were not updated correctly to the offline copy which created duplicates.
- Changing the value of "Show tray status icons" could not be done.
- Skin settings were not saved correctly if there were multiple instances of the same window active.
- Skin details show also the version history for the skin.
- Added event handlers for enabling/disabling calendars and refresh & quit Rainlendar.
- Updated to wxWidgets 2.9.4.