Explanation / #1566

It would be great to have a new column with the completion date (end date) of a task or project.
This column should have a sort-option.

This new column should be in the list:

1. home (my tasks)
2. projViewTasks (tasks of a project)
3. projList (projects)

The reason of the feature request is that:

1. the employee has the possibility to order his tasks in the sequence of their completion date (e.g. most urgent first)
2. the pm has an better overview over the completion sequence of the projects