Shortcode to render a link to an .ics calendar file.
I don't really understand PHP. It's weird.
[calendar start="31.12.2014 22:00" end="01.01.2015 05:00" title="Party"]
start
: Mandatory. Example: "31.12.2014 22:00". Has to be parseable by strtotime.end
: Mandatory. Example: "31.12.2014 22:00". Has to be parseable by strtotime.title
: Mandatory. Example: "Party"location
: Example: "Kugl, St. Gallen". Default: empty.description
: Example: "Incredibly awesome party.". Default: empty.link
: Example: "Incredibly awesome party.". Default: empty.filename
: Used for .ics file. Default: "entry.ics".linktext
: Title of download link. Default: "Add to calendar".linkclass
: CSS class applied to download link. Default: "calendar".