Creates an iCal feed with WP Calendar events.
The generated file contains iCal / RFC5545 / RFC2445 conform data, which can be imported in several Calendar applications like Outlook, iCal, Google Calendar.
WP Calendar 1.5.x and also older versions (like 1.4.x) are supported.
Based on iCal for Events Calendar.
Feed will be at http://your-web-address/?wp-calendar-ical