Optional email notification for students upon task update

Currently when an instructor updates the deadline of a task, an email is sent to all students in that group regarding the change.

This email notification should be configurable by the instructor upon making the change to the deadline. Often only minor changes are made, (e.g. small extension at the end of an exam) and instructors should have the right to decide whether an email notification for students are required or not.
This feature would also reenforce for instructors, that an email notification is sent upon the change - if they would like.