Added string validations for languages
Creating PreviousGrades object and seeds, and associated Student to it.
Added regex for letters, numbers, spaces, and dashes
Added validations for previous school/grade info
Updated controller to work for student previous grade/school workflow
Updated to use PreviousGrades plumbing
Removed old grade stuff
Added validations for student special services questions
Removed default values for IEP and 504 (the page would pre-populate a value based on the default)
Reformatted code for student_address (no functional changes)
Added street regex to model constants
Added validations for student address
Pass through following student confirmation screen
Fixed bug in seeds file around grades
Merge branch 'master' into student-address

* master:
  Removed grid classes from student name screen
  Updated grid styling and fixes for reset styles

Conflicts:
	app/views/enrollment/student_special_services.html.erb
Merge pull request #152 from codeforamerica/student-address

"Yellow Submarine" or Students all live at... validations and saving