WS30: Include ambient light in ALS fragment shader

Previously only the diffuse term was considered in the fragment
shader, leading to very dark scenery and deep shadows.

Now the ambient light term is also included making the scenery
much closer to the way it should be lit.

Shaders/ws30-ALS.frag

@@ -119,7 +119,7 @@ void main()
     vec4 mat_diffuse = texture(diffuseArray, index);
     vec4 mat_specular = texture(specularArray, index);
 
-    vec4 color = mat_diffuse * NdotL *  gl_LightSource[0].diffuse;
+    vec4 color = gl_Color + mat_diffuse * NdotL *  gl_LightSource[0].diffuse;
 
     // Testing code:
     // Use rlc even when looking up textures to recreate the extra performance hit