Fix broken layout in Gradebook (SIS ID column)

Re-add SFU MOD, and adjust settings to make the SIS ID column work with
the new slickgrid/frozen column implementation.

It is now compatible with the 12/28/13 release by Instructure.
Merge pull request #139 from va7map/canvas188-re_fix

Fix broken layout in Gradebook (SIS ID column)