Update calendar view to current Date and Calendar releases

A lot has changed in the Date and Calendar modules and we need to update our default event_calendar view accordingly.

Steps:

• Create a new view using the (nice!) calendar views template for the field_event_date field.
• Configure the new view to have some of the customizations we'd previously made.
• Export the new view, manually editing its name to be the same as the existing default view (event_calendar), and copy it over the old view.