Glyph loading fixes and improvements (for Unicode fonts).

- Glyphs are now loaded for specific fonts as needed, not for all of them at once.  This reduces lag and saves memory.
- Fixed glyphs not being loaded in the downloads menu.
- Moved Utils.loadGlyphs() calls directly above text drawing code (easier to maintain, and fixes a bug with text flickering once).

Also removed MusicController methods 'getTrackName()' and 'getArtistName()' (not needed).

Signed-off-by: Jeffrey Han <itdelatrisu@gmail.com>

src/itdelatrisu/opsu/downloads/DownloadNode.java

@@ -332,6 +332,8 @@ public class DownloadNode {
 		textX += img.getWidth() + buttonWidth * 0.001f;
 
 		// text
+		if (Options.useUnicodeMetadata())  // load glyphs
+			Utils.loadGlyphs(Utils.FONT_BOLD, getTitle(), getArtist());
 		Utils.FONT_BOLD.drawString(
 				textX, y + marginY,
 				String.format("%s - %s%s", getArtist(), getTitle(),