try to fix db migrate bug but failed
db schema.rb
final merge 5 projects except 1459
Merge remote-tracking branch 'e1483/rails4' into rails4

Conflicts:
	Gemfile
	Gemfile.lock
	config/database.yml.example
	test/functional/student_quizzes_controller_test.rb
	test/test_helper.rb
Update the email address used by the mailer test
Update the migrations to the rails4 branch