End Date for Repeating Events (10 est.)

[leoselig]

As a user I want to specify an end date for an event series during the creation/edition so that I don't have to delete a series from at a certain point.

Hints:

• Take Google Calendar as a guidance!
• don't mix up the end date with the start/end times of an event (these refer to each occurance)

Acceptance Criteria:

• Input for end date is only available if repition is enabled
• Input for end date is a date/time picker (cross-browser)
• Calendar and list of upcoming events do not show any occurances happening after the end date
• End date is visualized on the event/occurance pages