Merge pull request #5 from pbl-cloud/wrapup

リファクタリング・モジュール化・機能追加
Update README.md.
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.
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.