Add calendar to df_tools_events

[rlnorthcutt]

We need to extend the events content type to offer a calendar option. The best looking option I can see is: https://www.drupal.org/project/fullcalendar_view

Ideally, we set this up with some common views pages that use the existing event content type, so we can reuse it for any scenario that enables df_tools_events OOTB. The events may change, but the calendar does not!

[saltednut]

This is a very common request. I am not up to date with the calendar solutions that are out there in the module world but I assume whatever has the high install rate is probably pretty easy to use.