Add model: courseware, exam, message, notify
Add controller and views of coursewares, exams, notifies, messages.
Rewrite coursewares, notifies as sub resource of courses.
Modify teacher/courses/exams controller and views.

	Now it can view in teachers' view, but lack of nested resourses:

	:questions, :records.

	Need to be added.
Modify teacher/courses/messages controller and views.
Add magic-encoding to Gemfile, and refresh *.rb files.
Add resources :questions to exam.
Add sub resourses records to exam.
Delete unused records views.
Modify orders of course sub resources.
fix new hash style to old hash style
Update admin/courses controller and views.
Mostfully comleted alpha version.
---------------------------------
Next to do:
	* find a better way for examing.
	* change styles using bootstrap.
Merge branch 'dev'

	Now this version can run, and its mostly like the one
	completed at 2007.