Deleted unused database.
Fixed incorrect imports.
Added sign in view.
Updated sign in view.
Added connection class for server.
Added class for the result.
Added toolbar to sign in page.
Added register view controller.
Able to load register view in sign in view.
Added function to post data to server.
Able to register account.
Fixed connection result that can extract data from response.
Able to register and popup result.
Successful registration will go back.
Updated register view controller.
Dismissed keyboard when tapped other space.
Password textfield is secured.
Added option to connection to use localhost.
Updated sign in view controller.
Dismissed keyboard when tapped other space.
Password textfield is secured.
Open sidebar menu when menu button is clicked.
Removed unused code in register view.
Updated function names.
Simplified codes in connection class.
Show dialog when sign in is clicked.
Focus on username on loaded.
Adjusted toolbar position.
Updated register view api endpoint.
Save username if registration succeeded.
Load saved username when sign in page is loaded.
Hide keyboard when buttons are clicked in sign in view.
Merged with Tianqi's code.