Small refactoring and functionality add in database_connector.py.
Use more generic methods for database accesses.
Fix bug in object hydration.
Handle login/logout properly.
Fix models.
Fix validation.
Remove done TODO.
Fix views.py.
Move logic out from views.py.
Handle authentication.
Merge pull request #6 from pbl-cloud/webapp_improvement

Added registration and login/logout functionalities
Change queue manager to update stdout and stderr.
Remove unused methods and upate tests.
Refactor ORM to use kwargs instead of dictionary.
Fix README.md.
Remove unused method.