Need non-AWT ways to get display count, width, height, pixel density

Created by: benfry

We need either 1) an alternative/native method to make these work, or 2) a per-Surface version of them.

The second option is still problematic since we don't know what PSurface will be used when settings() is called. So either we need to start passing that to the command line, or do something more clever, i.e. once size() or fullScreen() is called, use the renderer to create an object that can handle these device settings on a per-surface type basis.

For now, displayWidth and displayHeight will be 0 when --disable-awt is used.

Empieza siguiendo cómo se gestionan displayWidth, displayHeight y la densidad de píxeles cuando se usa --disable-awt; después, examina las rutas size(), fullScreen(), renderer y PSurface mencionadas en el issue. Se considera terminado cuando se proporcione una implementación no-AWT definida o un enfoque viable por Surface, en lugar de devolver 0 para las dimensiones de la pantalla.