Text shadow and Event description

• "Text shadow" option added to Colors section with these values: "No shadow" (default, nothing changes for existing widgets),
  "Dark shadow" and "Light shadow". For simplicity the same shadow applies to all parts of the widget.
  #88
• Event details -> "Description" option added to show Calendar event Description.
  #78
• Added settings to limit maximum number of lines for an event's title and for details (i.e. for time,
  location and description). #109.