Integrated evaluatee selection
Added some admin models
Modified COGS model, added more admin models
Made student field of AttendanceForm readonly/disabled
Undid modification from previous commit, altered student widget to obtain similar result
Added csv files, moved volunteer field to Evaluation model
Modified template to include volunteer checkbox
Added initial code for csv parsing
Added model parsing for students, COGS, Groups
Added more code to the parser function
Added number field to TA model
Modified views to accommodate changes
Added basic tests