[SpeedGrader] Display Assignment Description in SpeedGrader

[douglas_rolley]

Problem statement:

When grading Assignments in SpeedGrader, one must open a new window to see all the Assignment description and requirements as presented by the instructor to the student.

Proposed solution:

Allow users to view the Assignment description, without leaving SpeedGrader or opening a new tab or window, when viewing submissions in SpeedGrader.

User role(s):

admin,instructor