modifications
Added model diagram.
Update README.md
Fixing Stuff => Staff
Fixing merge

Conflicts:
	tutor/app/models/staff.rb
	tutor/app/models/test_case.rb
	tutor/db/migrate/20140323113417_create_test_cases.rb
	tutor/db/schema.rb
fixing error
Merge branch 'dev_models' of https://github.com/alaashafaee/Coolsoft-14 into C3_Rami
fixing many Lecturer_Topics
fixing TA has many courses
Merge pull request #147 from alaashafaee/dev_models

Dev models
adding TrackProgression model
Merge pull request #148 from alaashafaee/dev_models

Dev models
Almost halfway through Issue #102
Merge branch 'master' into C3
Merge branch 'C3' into C3_Rami
Halfway through Issue #102
Removed test code from site controller. Issue #102
Updated models. Documented created methods. Issue #102