Allow the submissions filter to sort by more than just first name

[acbart]

The submissions filter is very badly coded; that whole section probably needs to be reorganized a little. But at the very least, allowing them to sort by last name would make SO much more sense.

[MrMazzone]

In addition to sorting by last name, I would like to be able to setup sections of students to view only a set of students in a course section at a time on the submissions filter page.

The section creation may need to be complete on the "Manage Students" page, where you can select a section number for each student.

Then, on the "Filter Submissions" page you can see all students in a course (default/blank option) or select a specific section.