admin/teachers_controller.rb :  redirect unless current visitor admin.
admin/teachers_controller.rb :  whitespace.
student_permission_form.js.coffee.erb : For managing permission_forms.
admin/teachers/_show_student_html.haml  cleanup form for serialization.
admin/teachers_controller.rb update_student_permissions action added.

[#50555503]
https://www.pivotaltracker.com/story/show/50555503