Remove addUser method, add beforeSave method in user model
Add validatePassword method to user model
Add default scenarion in user model
Change RegistrationForms parent to user model
Delete properties of registrationForm which duplicate user model
properies
Add conversation model and delete useless link in message model #17
Merge branch 'register'

Conflicts:
	app/models/RegistrationForm.php
	app/models/User.php