Refine models.

- Destroy dependent objects wherever required.
Refine models.

- Remove redundant has_many relationships.
Refine default data yaml.

- Add data for roles.
Remove redundant method.

- Remove redundant method.
Refine default data creation logic.

- Refine logic for role creation.
Add methods to delete default data.

- Add methods to delete default data.
Add yaml for default users and roles.

- Add yaml for default users and roles.
Add yaml for default classes and students.

- Add yaml for default users and roles.
Add yaml for default study materials.

- Add yaml for default study materials.
Add yaml for class assignments.

- Add yaml for class assignments.
Add yaml for learner and their responses.

- Add yaml for learner and their responses.
Refine default data creation.

- Refine default data creation to work with separate yaml files
  for default data.
Merge branch 'test_data_reset_04_08_2013_a'

- Merge branch 'test_data_reset_04_08_2013_a'
  into test_data_reset_04_17_2013_a.

- Conflicts:
    features/step_definitions/downloaded_file_steps.rb
    features/student_runs_jnlp.feature
Refactor default data creation.

- Minimize calls to recursive_symbolize_keys method.
Refine default data creation.

- Print object insertion status for some objects.
Merge branch 'test_data_reset_04_08_2013_a'

- Merge branch 'test_data_reset_04_08_2013_a'
  into test_data_reset_04_17_2013_a.
Update task log message style.
Add progress status messages to task.

- Update status messages for portal schools
  and portal courses.

- Add status messages for users, teachers and students.
Refine default user data yaml.

- Make all uuid 36 characters long.
Refine default data creation

- Refine default users yaml.

- Print insertion status of objects.