Added hover stack to manage overlapping Area2Ds

Added room selector in demo scenes
Modified dialogues in room 1, fixed bug in room 8 and 9

addons/escoria-core/game/main.gd

@@ -179,3 +179,8 @@ func check_game_scene_methods():
 	assert(current_scene.game.has_method("inventory_item_unfocused"))
 	
 	assert(current_scene.game.has_method("mousewheel_action"))
+	
+	assert(current_scene.game.has_method("hide_ui"))
+	assert(current_scene.game.has_method("show_ui"))
+	assert(current_scene.game.has_method("_on_event_done"))
+