[OBMFULL-5872] - Clicking the "email" badge should open the first unread email
OBMFULL-2949 Can invite an attendee without email.
OBMFULL-3315 Display first occurence in UI.

With a weekly event, display the first occurrence even when it occurrs on a
different weekday than the ones picked for repetition.
OBMFULL-6001 Removes infinite loop in obm-conf packaging.

This prevented the obm-conf installation from terminating when using the
non-interactive frontend on Debian.
OBMFULL-6002 Correct display in resource screens.

Previously, the lang labels for the resources were overwritten by the
calendar's.