Add ability to assign different assignments or time limit to students with accommodations

[barbarer]

I used to just create several versions of an assignment with different times for a timed exam and send an email with the correct URL to the students with accommodations, but this ability was removed.

I still need a way to not make an assignment visible to all students but make sure that some students can see it and take it. It would be nice if I could also specify the length of time for those students, if it is a timed exam.