整理代码，音乐室三个按钮改用图标

parts/language/lang_en.lua

@@ -546,8 +546,6 @@ return{
 		dict={
 			title="TetroDictionary",
 			link="Open URL",
-			up="↑",down="↓",
-			pageup="↑↑",pagedown="↓↓",
 		},
 		stat={
 			path="Open Data Folder",
@@ -559,9 +557,6 @@ return{
 			now="Now Playing:",
 
 			bgm="BGM",
-			up="↑",
-			play="Play",
-			down="↓",
 			sound="SFXs",
 		},
 		sound={

parts/language/lang_fr.lua

@@ -515,9 +515,6 @@ return{
 			now="En train de jouer :",
 
 			bgm="Musique",
-			up="↑",
-			play="Jouer",
-			down="↓",
 			-- sound="SFXs",
 		},
 		sound={

parts/language/lang_symbol.lua

@@ -371,9 +371,6 @@ return{
 			now="~:",
 
 			bgm="#~#",
-			up="↑",
-			play="!!!",
-			down="↓",
 			sound="=><=",
 		},
 		sound={

parts/language/lang_zh.lua

@@ -543,9 +543,6 @@ return{
 			now="正在播放:",
 
 			bgm="BGM",
-			up="↑",
-			play="播放",
-			down="↓",
 			sound="音效",
 		},
 		sound={
@@ -623,8 +620,6 @@ return{
 		dict={
 			title="小Z方块词典",
 			link="打开链接",
-			up="↑",down="↓",
-			pageup="↑↑",pagedown="↓↓",
 		},
 		stat={
 			path="打开存储目录",