Consolidating the recurrence button definition
Changed styling of the recurrence indicator

The red color was a bit alarming and competed for attention with the
overdue deadline indicator. The cursor on hover is now also changed to
indicate that it's merely for information - shows the period of
recurrence.
Adding information about the exact deadline

Hovering overe the deadline will now show the full date, even when the
human readable version is presented. The cursor also changes in line with
how it works for the recurrence button.