Implement KeyListener

This will listen for keyboard actions.

Signed-off-by: Ino Gamalinda <ino.gamalinda@teamcodeflux.com>
Switched JWindow to JFrame

Because JWindow doesn't seem to respond on KeyListeners, it might be a bug or a feature.
Close the frame when Escape button is released.

Signed-off-by: Ino Gamalinda <ino.gamalinda@teamcodeflux.com>
Created Screen Dimension Helper

Will be used for getting the screen size and positions.
Utilize the screen dimension helper

For code reuse