Multiplayer improvements and reupload score on error

- In multiplayer you will play at the bottom if you joined second
- Add a dialog to song select that score has not been saved
- Uploads the score when logged in again
- Translate error messages from the server

public/src/js/assets.js

@@ -1,7 +1,6 @@
 var assets = {
 	"js": [
 		"lib/md5.min.js",
-		"lib/js.cookie.min.js",
 		"loadsong.js",
 		"parseosu.js",
 		"titlescreen.js",