OBMFULL-2949 Can find a UserAttendee by login.
OBMFULL-2949 Can delete an event with attendee without email.
OBMFULL-6086 Use '~' for DB upgrade scripts.
OBMFULL-4160 Correct backup of contacts from another domain.
OBMFULL-4160 Correct restoration of events from another domain.
OBMFULL-4160 Correct restoration of contacts from another domain.