Add missing items (in English) to Japanese translation file

Author: terrill

translations/ja.js

@@ -12,6 +12,16 @@ var ja = {
 
 "stop": "停止",
 
+"restart": "Restart",
+
+"prevChapter": "Previous chapter",
+
+"nextChapter": "Next chapter",
+
+"prevTrack": "Previous track",
+
+"nextTrack": "Next track",
+
 "rewind": "巻き戻し",
 
 "forward": "早送り",
@@ -72,6 +82,10 @@ var ja = {
 
 "spacebar": "スペースキー",
 
+"transcriptTitle": "Transcript",
+
+"lyricsTitle": "Lyrics",
+
 "autoScroll": "自動スクロール",
 
 "unknown": "不明",