remove game state classes

scripting improvements

data/modules/mainmenu/menustate.lua

@@ -0,0 +1,20 @@
+-- menu state
+function onEnterMenuState()
+    MainMenu_create()
+end
+
+function onLeaveMenuState()
+    MainMenu_destroy()
+end
+
+function onApplicationClose()
+    onLeaveMenuState()
+    exitGame()
+end
+
+-- here is where everything starts
+if not initialStateLoaded then
+    onEnterMenuState()
+    setOnApplicationClose(onApplicationClose)
+    initialStateLoaded = true
+end