SoundBuffer: Set song volume

- Requires a new column in the database after preview: `volume` REAL
- The value is a volume multiplier, if the value is set to null or 1 there will be no change
- The volume can be set in debugger
- Imported TJA files are now read from disk every time the song is played, freeing some memory and making it easier to create charts
- Correctly parse TJA files with alphabet notes, added "A" and "B" notes, which appear as DON (Big) and KA (Big) respectively

public/src/js/about.js

@@ -143,7 +143,7 @@
 			}
 		}
 		
-		var issueBody = strings.issueTemplate + "\n\n\n\n" + diag
+		var issueBody = strings.about.issueTemplate + "\n\n\n\n" + diag
 		this.getLink(this.linkEmail).href += "?body=" + encodeURIComponent(issueBody.replace(/\n/g, "<br>\r\n"))
 		
 		return diag