Allow Attendance Tool to have more vertical height

In the Original Course View, at least, the attendance tool loads as a div inside the page itself, which is shorter in height than the page itself.  This leads to an awkward interface with multiple scrollbars.

For larger classes, allowing the attendance panel to use more vertical space on the page would improve an instructor's ability to view their more of their student's at one time.  This is especially helpful in courses where an instructor marks students as present without necessary calling roll.