Enable Product Owners and Contributors to mark To-dos assigned others as complete via the primary check-box

We often check off To-dos during a collaborative status meetings.  The person who is checking off the To-do is the person sharing their screen with others in the meeting and not the owner of any/most of the To-dos being checked off.  However, the person is an Aha! user with Product Owner or Contributor rights to the product that the To-Dos are associated with.

Currently, a user can only mark a To-do that is assigned to another user as complete if they drill into the To-Do details and check the box next to the name of the user it is assigned to. 

This means the person checking-off multiple To-dos has to open each To-Do rather than checking off the To-do via the primary check-box next to each To-Do in the list of To-Dos that appears in the Feature view.

It would save us time and improve the UX if the user could check this primary check-box instead of having to drill into each To-do's details every time.

Note that this is already the behavior for To-dos that are not assigned to anyone - just not for To-dos assigned to someone else.