Added STATUS_NO_SESSION status code.
Changed gitignore file.
[ENHANCEMENT] - Returns User model after login.

* Description:
API end now will return an User model if user signed in successfully.
The User model is necessary for the client side.
[COMPONENT] - The UI code.

* Description:
The UI end code contains basic AngularJS/Bootstrap structures, useful
functions/constants/directives, and a completed login page.