Add RectangularPaddle.
Make specs for game objects.
Use gosu to draw on screen. Make the ball move.
Add physical shapes and bodies to the paddles and balls.
Make the paddle follow the mouse.
Merge branch 'gosu' into dev
Make sure the ball doesn't stick in the walls.
Add some basic configuration methods.
Make it possible to configure the camera.
Draw configuration messages in the UI.
Make a simple key-value storage on top of sqlite3.
Have the game collect its configuration from the database if available. Display the registered coordinates of the fiducial as recorded by the camera during configuration.