1. add model student, teacher

2. add controller login

3. set login#welcome to root route
1. Add admin to models

2. Make login/logout useable
Add new model: Course

	Course -- teacher  n:1
	Course -- student  n:n  ==> courses_students
Add HABLT relationship between Course and Student.
Add course and its relationship
Rename README.rdoc to README.md
Add controllers:

	admin/students
	admin/teachers
	admin/courses
Add files not tracked by previous commit.
Merge branch 'dev'
	now it can login add do something.