Refreshed a few menus, stubbed Settings menu

lib/ui/menus/main_menu.rb

@@ -1,13 +1,17 @@
 class IMICFPS
   class MainMenu < Menu
     def setup
-      title "I-MIC FPS"
+      title IMICFPS::NAME
 
       link "Single Player" do
         push_state(LevelSelectMenu)
         # push_state(LoadingState.new(forward: Game, map_file: GAME_ROOT_PATH + "/maps/test_map.json"))
       end
 
+      link "Multiplayer" do
+        push_state(MultiplayerMenu)
+      end
+
       link "Settings" do
         push_state(SettingsMenu)
       end