Minor updates.

- Draw the playfield background in the song menu if a background cannot be drawn for the focused beatmap.
- Added ScoreDB.deleteScore() method to delete a score from the database.
- Added @author tags for curve-related classes (by fluddokt, #12).

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

src/itdelatrisu/opsu/objects/curves/Bezier2.java

@@ -20,6 +20,8 @@ package itdelatrisu.opsu.objects.curves;
 
 /**
  * Representation of a Bezier curve with the distance between each point calculated.
+ *
+ * @author fluddokt (https://github.com/fluddokt)
  */
 public class Bezier2 {
 	/** The control points of the Bezier curve. */