Create Offline Calendar [feature request]

[wayneoutthere]

Currently we can only add an offline calendar (like this French screenshot here)

Some users do not like security/method of currently available calendar syncs and wish to be able to manually add offline calendars.

Please add 'Add new (Offline) calendar' feature to go with 'Add Online' Calendar

[hummlbach]

I also left a comment concerning addition of local calendars in #15. At the moment its only possible to do it from shell by:
syncevolution --create-database backend=evolution-calendar database=NameOfCalendar