Custom scripting, #song=, translations

- A song can be linked directly by adding "#song=<id>" to the url, replace `<id>` with the id in the database, after loading it jumps immediately jumps to the difficulty selection
- Added tutorial translations
- Fixed song preview not playing
- Use text fallback for the logo when there are no vectors
- Increased combo cache by 1 pixel
- A custom javascript file can be loaded from config.json by defining "custom_js" value
- Added lots of events to help writing custom js files: `version-link, title-screen, language-change, song-select, song-select-move, song-select-difficulty, song-select-back, about, about-link, tutorial, import-songs, import-songs-default, session, session-start, session-end, debug, load-song, load-song-player2, load-song-unfocused, load-song-cancel, load-song-error, game-start, key-events, p2-game-end, p2-disconnected, p2-abandoned, pause, unpause, pause-restart, pause-song-select, game-lag, scoresheet, scoresheet-player2`
- Event syntax example:
```js
addEventListener("game-start", event => {
	console.log("game-start", event.detail)
})
```

public/src/js/tutorial.js

@@ -1,6 +1,7 @@
 class Tutorial{
-	constructor(fromSongSel){
+	constructor(fromSongSel, songId){
 		this.fromSongSel = fromSongSel
+		this.songId = songId
 		loader.changePage("tutorial", true)
 		assets.sounds["bgm_setsume"].playLoop(0.1, false, 0, 1.054, 16.054)
 		this.endButton = document.getElementById("tutorial-end-button")
@@ -47,6 +48,7 @@ class Tutorial{
 		this.gamepad = new Gamepad({
 			"confirm": ["start", "b", "ls", "rs"]
 		}, this.onEnd.bind(this))
+		pageEvents.send("tutorial")
 	}
 	insertText(text, parent){
 		parent.appendChild(document.createTextNode(text))
@@ -66,7 +68,7 @@ class Tutorial{
 		assets.sounds["se_don"].play()
 		localStorage.setItem("tutorial", "true")
 		setTimeout(() => {
-			new SongSelect(this.fromSongSel ? "tutorial" : false, false, touched)
+			new SongSelect(this.fromSongSel ? "tutorial" : false, false, touched, this.songId)
 		}, 500)
 	}
 	clean(){