Added naive User model
Added abortIfNotExists method and user resource
Added users resource on API
Added a model to prevent fake/spam users.
-Changed the user-creation method, now needs 2 steps to complete.
-Added url /createUser to activate users using a key.
-Added a method which generates random codes
Added passwords
Fixed wrong spelling
Removed white-lines and solved user-creation conflicts.
updated README.rst
Merge remote-tracking branch 'origin/users_feature'

Conflicts:
	shiva/app.py
	shiva/resources.py