Let the game engine manage it's own sound scene. This is to fix bug 1415 (Patch from Peter den Bak)

http://projects.blender.org/tracker/index.php?func=detail&aid=1415&group_id=9&atid=125
Also release the OpenAL device & context.  These were leaked before, and would cause an assertion.

source/blender/src/space.c

@@ -456,9 +456,9 @@ void start_game(void)
 	scene_cfra_store= save_and_reset_all_scene_cfra();
 	
 
-	/* sound init is save, only handles once */
-	sound_init_audio();
+	/* game engine will do its own sounds. */
 	sound_stop_all_sounds();
+	sound_exit_audio();
 	
 	/* Before jumping into Ketsji, we configure some settings. */
 	space_set_commmandline_options();