Add in the default configuration first extensions and mimetypes used when uploading a calendar
Add to the internal API a method to parse a ical stream and save the meetings into the db
Add template to upload a iCalendar file
Define the form used when uploading an iCalendar
Add method in the controller to upload an iCalendar file

- Change the agenda to only display the first 22 characters of the meeting summary as
otherwise the page becomes clumsy

- Add link in the admin panel to the page where they can upload an ics file

- Fix the mardown conversion when no meeting description has been entered

- Validate the submitted iCalendar file by file extension and mime type

Fixes https://fedorahosted.org/fedocal/ticket/32
Fix the iCal output when there is no description associated with a meeting.
Fix english typos -- thanks @ralphbean
Merge pull request #81 from fedora-infra/upload_ics

Upload ics