Began part 3.3: ambient light is black now. night and day texture are loaded and created.
 BUGS: 1.Texture steht auf dem Kopf.
2. Nightlights Texture is allover the spehere because it is in the ambient term. Light calculation needs a new or angepasste  function.
3. there must be a smooth transition betweeen day and night texture like it's written in the task