…fic meeting

To delete a specific meeting in a recursion we split the recursion into
two and drop the meeting in the middle.
But to do this, we need to know the from_date argument.

The agenda view had this working but for some reasons it was missing from
the list view.

…he template

Show the date of the meeting that will be deleted as well as the date
of the original object/meeting as stored in the database

…om_date)

Without lifting this restriction, we are no longer able to delete meeting
from the past that occurred as part of a recursion.